问题 单项选择题

用35%或37%的磷酸进行酸蚀的合适时间是

A.恒牙1分钟,乳牙20秒

B.恒牙20秒,乳牙1分钟

C.恒牙40秒,乳牙10秒

D.恒牙10秒,乳牙40秒

E.恒牙乳牙均为1分钟

答案

参考答案:B

阅读理解

阅读理解

Dear sir,

     I have to travel every day from Souk Road to the airport. Two buses travel along the routes: the

number 49 and the number 16. But by the time the number 16 bus reaches Souk Road. It is always

full, so I can't get on it. I have to wait for the number 49 because sometimes there are empty seats in

it. The timetable says that there are buses from Souk Road to the airport every ten minutes. If this is

true, why do I have to wait half an hour for a us nearly every day?

     The rules say that if there are empty seats on a bus, the bus must stop at every stop where people

are waiting. Why do the half-empty buses go straight past me when I am standing at the bus stop. The

rules say that no bus may carry more than 40 seated passengers and 20 standing passengers. Yesterday

I was the first to get off the bus when it reached the airport. I counted the other passengers as they got

off. There were 129 people.

     It is clear that our bus companies break the rules and think little of their passengers. Can nothing be

done to make your service better?

1. This passage is __________.

A. a message

B. a talk

C. a story

D. a letter

2. The writer has to take Bus No.49 because __________.

A. it arrives on time

B. it is not always full

C. it travels faster

D. it has fewer seats on it

3. How long does the writer usually have to wait for a bus?

A. Ten minutes

B. One hour

C. Half an hour

D. Nearly a day

4. The rules say that each bus may carry __________ passengers at most.

A. twenty

B. forty

C. sixty

D. one hundred and twenty-nine

5. From the passage we can see that __________.

A. the bus service was poor

B. no passengers took their buses

C. no buses except the No.49 bus passed Souk Road

D. the writer was always the first to get on the bus

选择题