柴油的十六烷值反映其（）A.着火性能 B.抗爆性能 C.安全性能 D.点火性能

配电变压器是利用电磁感应原理工作的，所以可以改变（）

A.电压

B.频率

C.波形

原核微生物细胞核糖体大小为（）

A.30S

B.50S

C.70S

D.80S

E.60S

城市道路横断面的选择与组合主要取决于()。

A．道路的性质、等级和功能要求

B．交通畅通和安全的要求

C．环境和工程设施的要求

D．A和C

阅读理解。

     Two thieves came to a house to steal something. They dug a hole in the wall of the house.

     There lived many mice in the house. The woman in the house saw a mouse crawl(爬行) into

the house in the moonlight. "Look! In comes one," she said to the man in the house. The thief was

so frightened that he hurriedly crawled out of the house and said to the one waiting outside, "She

found me when I was just in." But the thief outside didn't believe him, so he said, "Let us try to

crawl into the house together." At that time two mice happened to crawl into the house, too.

The woman saw the mice and shouted, "In come two, catch them!" The two thieves were

terribly frightened. The man in the house said, "You saw them come in but where are they?

I will catch them tonight." The two thieves started running away at once.

     The two thieves wanted to make it clear whether they had been found or not the night

before. The next day they acted as men selling sweet potatoes and came before the house.

The man and the woman were ploughing in their fields. The rope broke and the woman came

home for a rope. She saw two men selling sweet potatoes and wanted to buy some. She

picked out two which looked like mice. At the time the man couldn't wait for her any longer

in the fields and he ran back from the fields to hurry her up. The woman showed the sweet

potatoes to the man and said, "How they look like the two of last night." The man said, "I

asked you to fetch a rope, why don't you hurry for it?" The two thieves ran away very quickly

without their sweet potatoes.

1. The two thieves failed to steal anything from the house because _____.

A. they were found out

B. they were frightened by what they had heard in the house

C. they didn't work together well with each other

D. mice stopped them from doing so

2. From the last paragraph, we know that _____.

A. the two thieves were famous selling sweet potatoes

B. the woman recognized the two thieves

C. the woman pretended to know nothing about the two thieves and made fun of them

D. the two thieves didn't know that they were not found at all

3. When the woman said, "How they look like the two of last night!" _____.

A. she referred to the two thieves B. she meant nothing

C. she said it on purposeD. she referred to the mice

4. "____________"is the best title for this passage._____

A. Two Clever Thieves B. Terrible Mice

C. Hit the Mark by a Fluke(侥幸) D. A Clever Coupe

5. Which of the following statements is NOT true?______

A. The two thieves not only failed to steal things but also lost their sweet potatoes.

B. Whenever they found mice, the people in the house would try to catch them.

C. The two thieves ran away at once, because they thought the woman had seen them.

D. The man let the woman go home for a rope, which would be used for catching the thieves.

为了探究物质的燃烧条件，小明同学使用如图所示的装置进行实验．

（1）实验不久小明看到了预期的现象，因而他得出了物质燃烧的条件：

①______ ②______  ③______．

（2）实验A中，开始时红磷和水下白磷都没有燃烧，可是时间稍长红磷也着火燃烧起来了．实验结束后小明对“红磷为什么会燃烧？”进行了反思．如果让你做该实验，为了防止红磷着火燃烧，请你提出一点改进措施______．