Happy Children''''s Day

Children’s Day is June 1st. The day is for every child, it is the happiest day for the children _________________________ (世界各地).They can _____(跳舞), _____(唱歌), __________ (玩游戏) and go to the_____(动物园). Dear friends, what are you going to do and where are you going? 小飞象: Hello! What are you doing? : We’re rehearsing a play(排练话剧) for Children’sDay. : Yes. It’s very interesting. Do you have any plans? 小飞象: Oh! I’m practicing a song for that day. Happy Party 儿童…     

CONVERSATIONS

A A:You’re mad(=crazy,insane疯狂)!Stark(=completely),raving(狂乱地,疯狂地) mad! B:Oh,I don't know.Weird(=strange,odd,queer奇怪),maybe,but not mad. C:Nobody in his right mind would do a thing like that! A:It's so foolhardy (=foolishly bold,reckless 鲁莽的)man(伙计,非正式称呼).You could get hurt,and seriously. B:I know.My mother used to(经常)scold(挑剔,指责)me all the time about it. C:Well,she doesn't seem to have had any effect(效果). B:Actually,I listened to her a lot of the time,but,really,nothing serious has ever happened. A:All I can say is,"Somebody up there likes you!”(上帝保佑你,非正式用语)     

Study on the neurotoxic effects of low-level lead exposure in rats

Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.     

蚂蚁的故事

In America,there are many kinds 1 ants(蚂蚁).One of them2 very strong 3 cutting jaws(颚).These ants move in large groups.They 4 any animals 5 their way.They can even kill(杀死)and eatelephant!They can eat wooden houses!People are 6 of these ants,and     

A Clock Maze

Here is a clock.There is a maze(迷宫) on the face.Please play the game at once.Start in the center.Find Number 1 first,and then visit each number around the clock dial(钟面) in order (1,2,3,4 …) without passing through any higher number.For example:after visiting Number 3,you must pass through Number 4 next.You must not pass through Number 5 before visiting Number 4! But it's OK to pass through again the same number you have just visited.Good luck to you! Have fun!     

WTO

The World Trade Organization (WTO) , created on January 1,1995, is responsible for encouraging international trade to flow as freely as possible, making sure that trade agreements are respected and settling any disputes (争论).In the five years since its conception, the WTO has appeared as one of the world's most powerful economic organizations, taking its place alongside the World Bank(WB) and International Monetary Fund(IMF) (国际货币基金组织).The system of global rules for the international trading system, however, dates back half a century to 1948 when the General Agreement on Tariffs (关     

What Are You Crying for?

Mr Cook had a big shop in the centre of the city. Hewas 1____ at managing (管理) it. He made 2_____money and was one of the richest men there. Bad 3_____!One day a truck hit his car on a bridge and it fell into theriver. He lost his life in the accident. He left a lot of mon-ey to his 4____. The old woman lived in the beautifulhouse and had many valuable (值钱的) things. She 5______did any housework and 6____ an easy life.Several years later Mrs Cook died. And there was abig funeral(葬礼). All her relatives(亲戚) and 7____were told about it. They 8____ from far and near to the     

Cognitive Style and Learning Strategies JoAnn Salvisberg looks at current SLA theories and their possible applications to the classroom situation

People learn and process new information in different ways.For decades researchers have been studying and com- paring the personality traits any cognitive learning styles of students to discover any distinguishing trait patterns(i.e.more characteristic of academically successful students than other learners).Moreover,many believe that if the classroom envi- ronment and even the teachers'teaching style can be tailored to meet the students'learning styles,learning as well as the students'self-concept as a learner will increase (Corzza,Gustin and Edelkind,1995).This article will offer a brief overview of differences in style and strategies and discuss the implications for teaching.     

词形转换专练(英文)

用括号内所给单词的适当形式填空。1.Y ou m ustlisten to the teacher(careful)in class.2.Id like two(kilo)of(tom ato).3.—W hatdoes your father do?—H e is a(drive).4.—Thank you very m uch.—Its a(please).5.Thank(good).The kite is not(break).6.H ow m any(knife)do you have?7.A cathas four(foot).8.W hat about(play)basketballafter school?9.There are three(box)oforanges on the bus.10.I wantsom e(bottle)ofapple juice.11.Please look at the two pictures.Can you find five(different)?12.I think the s…     

Influences affecting the soil-water characteristic curve

INTRODUCTION The soil-water characteristic curve (SWCC) gives the relationship between the amount of water in the soil (i.e. gravimetric or volumetric water content) and soil suction (i.e. matric suction at low suction and total suction at high suction). Many properties of a partially saturated soil such as the coefficient of permeability, shear strength and volume strain, pore size distribution, the amount of water contained in the pores at any suction, can be obtained from the SWCC. …     

A Little Girl

Last Sunday Iwentto the big park nearm y home.Spring was com -ing.The grass started to come outand the trees turned green.There werem any flowers in the park.Som e people were watching the beautifulflow-ers and m any children were flying kites in the warm sunshine.H ow happythey were!“W hat beautiful flowers!” a good-looking wom an said. Then shewanted to pick a red flower.“Excuse m e,M adam .You m ustn't pick flowers!”A little girl tookherarm .She was only 5years old.Atfirst,the wom …     

Cognitive Style and Learning Strategies JoAnn Salvisberg looks at current SLA theories and their possible applications to the classroom situation

People learn and process new information in different ways.For decades researchers have been studying and com- paring the personality traits any cognitive learning styles of students to discover any distinguishing trait patterns(i.e.more characteristic of academically successful students than other learners).Moreover,many believe that if the classroom envi- ronment and even the teachers‘teaching style can be tailored to meet the students‘learning styles,learning as well as the students‘self-concept as a ...     

淡水--生命最后的边界

The final frontier for early animal life wasn’ta crawl(爬行)onto dry land,but theplunge(跳入,投入)into freshwater streamsand lakes,say Paleontologists(古生物学者). Although it took 100 million years for all ofthe major groups of animals to evolve from the firstmulti-celled creatures and crowd the world’soceans,it was a whole lot longer before any critters(生物)found ways to survive in fresh water.     

形容词副词专项练习

用所给形容词或副词的正确形式填空。1. My pen is(new) than his.2. Shanghai is(big) than any othercity in China.3. This bag is(small) of all.4. The girl is (beautiful) in the class.5. She gets up (early). Her fathergets up(early) than she. Her mothergets up the (early) of the three.6. Which do you like (well), this bag orthat one?     

how问句知多少?

英语中以how开头的疑问句很多,且有各种用法,现归纳如下:一、问候。1.用于初次见面时的问候。例如:—H ow do you do?你好!—H ow do you do?你好!2.问健康状况。例如:—H ow are you?你(身体)好吗?—Fine,thank you.And you?很好,谢谢。你呢?—H ow is yourfather?你父亲(身体)好吗?—H e is very well/OK.他很好。二、问年龄。例如:—H ow old is yourm other?你母亲多大了?—Shes forty(years old).她40岁了。三、问数量。1.用“how m any+可数名词复数”询问可数名词的量。例如:—H ow m any books are there in the box?箱子里有…     

Performance Improvement of Distributed Coordination Function in IEEE 802.11 Wireless LAN

This paper proposes a modification to distributed coordination function (DCF) to improve the channel utilization in IEEE 802.11 wireless local area networks (WLANs). In the modified DCF, when a station has contended for the channel, it may transmit multiple data frames continuously to the same destination, which is called transmission burst(TB). When the maximum number of data packets transmitted continuously in a TB is set to be 2, the performance is expected to be the best. The theoretical analysis and simulation results show that compared with the standard DCF, the modified DCF can increase the throughput and decrease the delay of the WLAN, and the modification does not introduce any additional control overhead.     

混合流体完备方程组的局部解析解

With the straification theory we have proved the transversal layer s03,k(D) of complete equations for mixed fluid is not an empty set: s03,k(D)≠φfor all k(k≥1). Based on this conclusion and the "secondary equation" of s03,k(D), this paper fully presents the expressions of coefficients in all local analytic solutions of the equations. Therefore we provide the calculation formulas by which we can get the numerical solutions to any desired accuracy.     

新目标英语八年级(下)单元测试题(Units 5～6)(英文)

Unit5Ⅰ.词汇(15分)A)根据汉语提示,写出空白处所缺的单词。(5分)1.We both like wearing(牛仔裤).2.Many people want to be professional(运动员).3.He said he himself(组织)the picnic carefully.4.The girl bought some(鲜花)for her mother on MotherIs Day.5.Both of his parents are(律师).B)根据句意和所给首字母,写出空白处所缺的单词。(5分)1.We won our match a that team yesterday.2.Is there any c of the team winning matches this week?3.I am going to MichaelIs birthday party t.4.Will you please e the third…     

攀岩——最值得考虑的事(英文)

As I sank, knee-deep, into another snowdrift two things simultaneously(自然地) occurred to(发生) me. Firstly, my boots, which I bought for ￡25 from a sports discount shop on Oxford Street, were definitely not water-proof(防水). Or even water-resistant. In fact they were like sponges, soaking any available moisture through the material into my freezing feet. Secondly, climbing mountains is not as easy as I thought. I had been attracted to the challenge with the thought of striding to the su…     

Instance-oriented delegation： A solution for providing security to Grid-based mobile agent middleware

INTRODUCTION Grid computing, since its emergence, has beenwidely regarded as a new revolution of informationtechnologies (Foster et al., 2001). Due to the highheterogeneity and complexity in Grid environments,mobile agent (MA) has been considered as one of thepromising solutions for realizing flexible and scalableGrid Computing. With the MA support, one canexecute parts of its program on any networked hostsoffering needed services. In the Grid world, applications usually need toget se…