下列面镜、透镜中，都能对光线起会聚作用的是　（） A．

搜题请搜索小程序“爱下问搜题”

问题选择题

下列面镜、透镜中，都能对光线起会聚作用的是　（）

A．凹镜、凹透镜

B．凹镜、凸透镜

C．凸镜、凸透镜

D．凸镜、凹透镜

答案

答案：B

凹镜和凸透镜都能对光线起会聚作用，选B

阅读理解

考考你的阅读能力。正确的写“T”，错误的写“F”。

Last month Mr. Black went to Canada. He didn't know Canada very well, so he lost his way (迷路).

Suddenly he saw a man " I can ask him the way.", he said to himself. " Excuse me!"he said." Can you tell me

the way to the 'King Street', please? " The man did not understand (懂，理解) English. He spoke French. Then

he took out a book. He opened the book and read a sentence (句子) slowly, " I'm sorry! " he said, " I don't

speak English."

( ) 1. Mr. Black went to France last month.

( ) 2. Mr. Black didn't know Canada very well.

( ) 3. The man took out a map.

( ) 4. The man didn't understand French.

( ) 5. The man is Mr. Black's friend.

单项选择题

对可撤销合同，具有撤销权的当事人应在 ( )内行使撤销权

A．合同成立之日起一年

B．当事人知道或者应当知道撤销事由之日起一年

C．合同成立之日起两年

D．当事人知道或者应当知道撤销事由之日起两年