单臂电桥平衡时，两个相对桥臂上电阻的乘积等于另外两个相对桥臂上电阻的乘积。（）

阅读理解。

     Dogs are friends of man. They work for us. They hunt with us. They also play with us. But a long

time ago, all over the world, dogs were wild. Dogs can go back to the Stone Age. All dogs had the

same ancestor (祖先). It is believed that this ancestor was much like a wolf. Other animals, like fox,

also came from this ancestor. Thousands of years ago, man began to tame (使驯服) the wild dogs.

When the dogs were tamed, they were trained (训练) well. The strong dogs then became working

animals. They were trained to pull heavy loads (担子). They learned to keep watching over sheep

and other animals. Working dogs could do other things, too. Some dogs were not strong. But they

could help man hunt. Other dogs were best at pets. At first, there were only a few kinds of dogs.

Today, there are more than 100 kinds.

1.The word "wild" in the first paragraph means _____.

A. 温顺的

B. 野生的

C. 凶残的

D. 善良的

2. Dogs can go back to the Stone Age. Here "go back" means _____.

A. 追溯到

B. 回来

C. 违背

D. 返回去

3. From this passage, we know that _____.

A. all the animals have the same ancestor

B. all dogs are as wild as they were many years ago

C. man has helped change animals

D. animals never change

4. What jobs can dogs do?

A. Keep watching over sheep.

B. Hunt with man.

C. Pull heavy loads.

D. All the above.

5. The main idea of the whole story is that _____.

A. man and dogs have the same ancestor

B. all animals are too wild to be man's friends

C. dogs and man have been friends for a long time

D. people like to keep foxes as pets because they are tamer

Ⅰ．如图所示A～H为实验室常见的仪器、装置（部分固定夹持装置略去），请根据要求回答下列问题：

（1）A仪器的名称是______，常用于______．

（2）用图中所示仪器设计一套制取一瓶干燥、纯净氨气的实验装置，仪器的连接顺序是（用管口字母符号表示）：j接______．

Ⅱ．为了研究Cl₂的性质，设计如图所示装置进行实验（装置Ⅲ中夹持装置已略去，其中a为干燥的品红试纸，b为湿润的品红试纸）．

（3）加入药品前，检查Ⅰ中气体发生装置气密性的操作是______．

（4）实验过程中，装置Ⅳ中的实验现象为______．

（5）实验结束后，该组同学在装置Ⅲ中观察到b的红色褪去，但是并未观察到“a无明显变化“这一预期现象．为了达到这一实验目的，你认为应在______之间（选填装置序号）还需添加一个洗气瓶，该装置的作用是______．

下列哪些不是办公用胶水的技术指标？（）

A.不挥发物含量

B.粘接性

C.防霉力

D.游离甲醛限量

十四、十五世纪的（）的第一个特点是没有稳定而长久的和平，没有严正的司法，不像我们有警察保护。

A.西班牙

B.意大利

C.法国

D.英国

接入网络的计算机除需要分配网络地址外，运行的每一个应用程序也必须有一个计算机内部唯一的地址，该地址被称为（）。

A.SAP或NSAP

B.SAP或Port

C.MAC或DTE

D.IP或NSAP