问题 选择题
在△ABC中,a=5,b=3,则sinA:sinB=(  )
A.
5
3
B.
3
5
C.
3
7
D.
5
7
答案

在△ABC中,∵a=5,b=3,则由正弦定理可得

sinA
sinB
=
a
b
=
5
3

故选A.

阅读理解

根据文章内容,判断正(T)、误(F)。

     Are you an impolite student? I hope your answer is "no"! What can you do to be a polite student? Have

you ever had these impolite behaviors?

     a. Do you usually play loud music in the evening?

     b. When you see the food you like, but there're many people waiting in line to buy it, will you cut in line?

     c. When you are eating food On the street, will you throw it on the ground?

     d. If you order a pizza half an hour ago, but it hasn't arrived yet, will you get annoyed?

     Manners are taught as soon as children can understand what parents are talking about. Maybe your father

and mother have told you thousands of times about what you should do and what you should not do. For

example, your parents told you that you shouldn't interrupt (打断) when your parents are talking.

     In some western countries, the first manner the children should learn is to make themselves clean. Parents

believe that keeping children clean is really important. Whether the children are at home or school, parents will

always tell them not to throw things at will (随意地).

( )1. It is OK to play loud music in the evening.

( )2. Manners are about what you should do and what you should not do.

( )3. It's impolite to cut in line when there are many people waiting in line to buy some food.

( )4. In Western countries, you can throw things at will when you are at home.

( )5. In the writer's opinion, if you want to be a polite student, you shouldn't have the four impolite behaviors.

判断题