问题 单项选择题 A型题

关于氨苄西林的叙述正确的是()

A.氨苄西林钠溶液的稳定性与浓度有关,浓度愈高,愈不稳定

B.水溶液稳定

C.氨苄西林钠具有α-氨基酸的性质

D.本品不具有其他青霉素的开环反应

E.本品为广谱天然青霉素,主要用于尿路感染、胆道感染等

答案

参考答案:C

解析:氨苄西林的水溶液不稳定,一方面发生青霉素的各种分解反应;另一方面室温放置生成无抗菌活性的聚合物。它具有α-氨基酸的性质,主要用于治疗肠球菌、痢疾杆菌等引起的感染。

阅读理解

阅读理解。

     Earthquakes may happen anywhere on the earth. When some plates of the earth move suddenly, an

earthquake happens. Many earthquakes begin under the sea. They often happen near the mountains, too.

     During an earthquake, the shakings make rocks rise suddenly and even crack (断裂) open. Houses

fall, people are killed or hurt, and sometimes the whole villages or cities are destroyed.

     Can we do something to keep ourselves safe from earthquakes? Scientists have studied earthquakes

and make maps that show the earthquake belts. In areas in these belts, it's possible for earthquakes to

happen. In these areas we should build strong houses to fight against earthquakes. In the future,

scientists will be able to tell when and where an earthquake will be before they happen. They can also

tell people what to do and how to do it.

1. The reason for an earthquake is _____.[ ]

A. that some plates of the earth move suddenly

B. that the sea is too deep

C. rocks' cracking open

2. A lot of earthquakes often happen _____.[ ]

A. in the area

B. next to mountains

C. at night

3. A map showing the earthquake belts will tell people _____. [ ]

A. what kind of houses to build

B. what kind of houses can stay up in an earthquake

C. where earthquakes may happen

4. Which is Not True according to the passage? [ ]

A. During an earthquake people are killed or hurt.

B. The scientists can tell when and where an earthquake is now.

C. We should build strong houses to fight against earthquakes.

5. In the future, we'll be no longer so afraid of earthquakes _____.[ ]

A. with the help of scientists' exact prediction

B. because of a map showing the earthquake belts

C. because we can guess the date and place of earthquakes

选择题