关于变电决策建议、输电决策建议的模块，这两个模块都有（）功能。

在△ABC中，A，B，C的对边分别为a，b，c且acosC，bcosB，ccosA成等差数列，则B=______．

第三部分 阅读理解（共两节，满分40分）

（共15小题：每小题2分，满分30分）

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。

Tt was a village in India. The people were poor . However, they were not unhappy. After all , their forefathers had lived in the same way for centuries.

Then one day, some visitors from the city arrived . They told the villagers there were some people elsewhere who liked to eat frog’s legs. However, they did not have enough frogs of their own, and so they wanted to buy frogs from other places.

This seemed like money for nothing . There were millions of frogs in the fields around, and they were  no use to the villagers. All they had to do was catch them . Agreement was reached, and the children were sent into the fields to catch frogs. Every week a truck arrived to collect the catch and hand over the money. For the first time ,the people were able to dream of a better future. But the dream didn’t last long.

The change was hardly noticed at first ,but it seemed as if the crops were not doing so well. More worrying was that the children fell ill more often ,and ,there seemed to be more insects around lately.

The villagers decided that they couldn’t just wait to see the crops failing and the children getting weak. They would have to use the money earned to buy pesticides （杀虫剂）and medicines. Soon there was no money left .

Then the people realized what was happening.Tt was the frog .They hadn’t been useless. They had been doing an important job-eating insects. Now with so many frogs killed , the insects were increasing more rapidly. They were damaging the crops and spreading diseases.

Now, the people are still poor .But in the evenings they sit in the village square and listen to sounds of insects and frogs. These sounds of the night now have a much deeper meaning.

1. From Paragragh 1 we learn that the villagers__________.

A.worked very hard for centuries

B.dreamed of having a better life

C.were poor but somewhat content

D.lived a different life from their forefathers

2.Why did the villagers agree to sell frogs?

A.The frogs were easy money.

B.They needed money to buy visitors.

C.They wanted to please the visitors.

D.The frogs made too much noise.

3.What might be the cause of the children’s sickness?

A.The crops didn’t do well.

B.There were too many insects.

C.The visitors brought in diseases.

D.The pesticides were overused.

4.What can we infer from the last sentence of the text?

A.Happiness comes from peaceful life in the country.

B.Health is more important than money.

C.The harmony between man and nature is important.

D.Good old days will never be forgotten.

某同学为了研究摩擦力做功，设计了如下的实验：将一个木块放在粗糙的水平长木板上，右侧拴一细线，跨过固定在水平边缘的滑轮与重物连接，木块左侧与穿过打点计时器的纸带相连接，长木板固定在水平试验台上，实验时，木块在重物牵引力下由静止开始向右运动，后因重物落地而做减速运动，下图给出了重物落地后打点计时器打出的一段纸带，纸带中一系列的小黑点是计数点，每相邻两个计数点间还有4个点（图中未画出），计数点间的距离如图所示。打点计时器所用交流电频率为50HZ。

（1）根据纸带提供的数据计算打点计时器在打下A点和B点时木块的速度V_A=____________m/s，V_B=____________m/s。（结果保留三位有效数字）

（2）由纸带运动情况可以得出，纸带做减速运动的加速度a的大小a=____________m/s²。（结果保留三位有效数字）。

（3）若木块的质量m，A、B间距离为l_AB，则木块在AB段克服摩擦力所做功的关系式W_AB=____________。（可选用V_A，V_B，m，，a，l_AB等物理量表示）

TCP/IP 参考模型中，应用层协议常用的有______。

A．TELNET，FTP，SMTP 和 HTTP

B．TELNET，FTP，SMTP 和 TCP

C．IP，FTP，SMTP 和 HTTP

D．IP，FTP，DNS 和 HTTP

美学包含着（）和（）。