遇到个别客人故意刁难服务员怎么办？

有一个带电量q=3×10^-6C的正点电荷，从电场中的A点移到B点，电场力做了6×10^－4J的功，求：

（1）A、B两点的电势差是多少

(2）若B点的电势为0，A点的电势以及此电荷在A点所具有的电势能是多少

A child-like robot, Wakamaru, developed by Mitsubishi Heavy Industries of Japan and combining the roles of nurse, companion and security guard, will soon be in the market to look after the growing number of old people with no one to look after them.

Cameras implanted under the “ eyebrows” of the robot enable it to “see’’ as it moves around in a house. The images can be sent to the latest mobile telephones, which can show the pictures. Wakamaru speaks with either the voice of a boy or a girl. It is also designed to provide companionship, greeting its “ papa”, when he comes home. Based on a vocabulary of around 10 000 words, it is the first household robot which is able to hold simple conversations. It can not only speak, but also understand answers and react accordingly. It will ask“ Are you all right?” if its owner does not move for some time. If the answer is no, or there is no answer, it will telephone preset numbers, send images and work as a speakerphone. It can recognize up to 10 faces. It can be set to remind forgetful people when it is time to take medicine, eat and sleep.

However, like most robots, it cannot climb stairs. Mitsubishi developed Wakamaru from robots which have already been made to go around nuclear power facilities(设施). “ Looking at the ageing of society and the falling birth rate we decided that this could work as a business. We want to offer it as a product that helps society,’’ said the project chief. The developers plan to sell the robot from April next year at between 5,000 and 6,000 pound.

The life expectancy of Japanese women has shot up to almost 85, the highest in the world. At the same time, extended families are being replaced by nuclear families. This has left many Japanese anxious about their elderly parents. Therefore, the technology has gained nation-wide publicity in Japan.

68.Which of the following is TRUE about Wakamaru?

A.    It is used in some nuclear power facilities.

B.     It can speak but cannot understand answers.

C.     It can go up and down the stairs easily.

D.    It can recognize as many as 10 people.

69.The passage is written with the purpose to ______.

A. introduce a new product  

B solve the aging problems.

C. tell people how to use the robot 

D show the rapid development of technology

70. What can be inferred from the passage ?

A. The robot can dial proper numbers for help

B. The robot is likely to have a promising market.

C. The robot enables the Japanese to live longer

D. Many elderly Japanese are anxious about their future

当建筑物桩基是以控制沉降为目的时，其桩距采用（）倍桩身直径。（）

A.6～8

B.4～6

C.3～4

D.1～3

　　有科学家认为，由父母选择基因“组合”下一代的时代已快来临了。在“组合”未来的“非常婴儿”方面，父母们面对的是一道多项选择题，他们可以选择让婴儿能抵抗常见疾病和感染的基因，这样婴儿不会害怕癌症、心脏病等；父母让孩子的个子长高一点、头发浓密一点也并非难事。

　　在美国的普林斯顿，科学家们成功地利用基因改善了老鼠的大脑功能，经过“加工”的老鼠比其他普通老鼠明显聪明得多。这种神奇的效果来自于从外界植入老鼠体内的一种基因，这种基因产生名为 NR2B的化学物质。人脑当然比老鼠的大脑复杂得多，但它们的工作原理实际上是一样的。

　　至于说到为孩子选择人格与个性，其实也不是匪夷所思的，专家相信，个人个性的特点中至少有一半是由基因的特性决定的。

　　科学家打算将来自不同个体的基因――比如聪明一些的和迟钝一些的，好看的和普通的――混合在一起进行研究，以便了解为什么人们会在力量、耐力、敏捷性等方面有差异。当这些主管天赋与性格的基因的奥秘解开之后，未来的父母就离“设计”自己的孩子又近了一步。但技术上的难题是，人为注入的基因大部分都是人体内自有的，因此如何确保这些外来基因能发挥作用，取代原来的基因是个关键。

　　有专家对基因工程能否如人们所认为的那样大步向前跃进持怀疑态度，因为在基因和染色体的世界里，随机性因素很多，基因一旦站错了队，不仅不能发挥出人们预先估计的作用，反而会给别的重要基因带来影响，甚至破坏它们。

　　要想给人的自然基因“升级”，只有通过“人造染色体”，可是人的染色体数目的标准是23对，加进人造染色体后，就必然引起染色体数量上的变化。如果未来人类还遵循有性繁殖规律的话，这些多出来的染色体还会传给下一代，这会带来什么后果多出来的染色体怎么办就是世界一流的科学家现在也无法对这些问题做出明确回答。

有些专家对选择基因“组合”下一代能够大步跃进持怀疑态度，对其原因理解正确的一项是（）。

A．因为如何确保外来基因能发挥作用，取代原有的基因这一关键问题尚未解决

B．因为在基因和染色体的世界里，随机性因素很多，基因一旦站错队，反而会起破坏作用

C．因为技术上的难题是，人为注入的基因都是人体内自有的，很难听人的安排

D．因为要想给人的自然基因“升级”，就必然通过“人造染色体”，而“人造染色体”的合成技术是个难题

斜管微压计的斜管不能倾斜得太厉害，一般不小于（）。

A.15°～20°

B.15°～25°

C.20°～25°

D.20°～30°