问题 实验题

多用电表是实验室和生产实验中常用的仪器之一,它具有测量电压、电流及电阻等多种测量功能。如图所示是多用电表的内部电路图,在进行电阻测量时,应将开关S拨到______________或______________两个位置;若测量电压时只有10V到50V两个量程,在测量时选择50V量程,应将开关S拨到______________位置;若测量电流时只有25mA和100mA两个量程,在测量时选择25mA量程,应将开关S拨到______________位置。

答案

3,4,6,2

阅读理解

阅读理解。

     Most people may not think that there are any problems with watermelons (西瓜), but some Japanese

sellers do. There is often wasted space when they store (贮存) watermelons, because round watermelons

do not sit nicely on shelves. So some clever farmers have solved the watermelon problem. They make their

watermelons grow in square glass boxes so the watermelons become square. The only problem now is the

price. The square watermelons cost about 80 dollars each.

     Many people know the saying "Roses are red, violets are blue, sugar is sweet and so are you". Well, today

the poem needs to change to "Roses are red, roses are blue"! Australian scientists have just recently discovered

that when they put a chemical from a blue flower into a rose, they can create a nearly 100% blue rose. Some

of science's inventions are beautiful, not just useful!

     Since the mid-1990s, many Chinese farmers have had amazing rice harvests. For many years Chinese

scientists have been working on developing new kinds of stronger rice and now they have produced a new

kind, called super rice. Super rice not only can protect itself against insects (昆虫) and diseases, but it also

produces more than any other kind of rice. Today farmers can grow almost one and a half times more rice

than they could grow in the past.

     Doctors might be able to use vegetables to fight cancer now. US scientists have discovered a way to put

a chemical into tomato plants while they are growing. When cancer patients eat the tomatoes, the tomatoes

will fight the cancer in their bodies. These cancer-fighting vegetables are not yet for sale, because scientists

have not finished testing them. If study finds no problems with the tomatoes, then patients can begin to use

this easy and delicious new treatment.

1. The square watermelons look like ____________.

A. B. C. D.

2. __________ find a way to make blue roses.

A. Chinese scientists

B. Australian scientists

C. American scientists

D. Japanese farmers

3. Which of the following is true?

 A. Super rice can keep itself from insects.

B. Blue roses are more beautiful than red ones.

C. The tomatoes can fight many kinds of diseases.

D. The square watermelons cost less than ordinary ones.

4. The main idea of this passage is ____________.

A. how scientists discover new plants

B. how science makes plants produce more

C. how science has changed plants and people's lives

D. how technology makes our world more beautiful

单项选择题