问题 填空题

下列命题:

①α内有无数条直线平行于β,则αβ;

②平行于同一直线的两个平面互相平行;

③经过平面α外两点一定可以作一个平面与α平行;

④平行于同一个平面的两个平面平行.

其中不正确的命题为______.

答案

①根据面面平行的判定定理可知,和平面平行的直线必须是相交直线,否则α,β不一定平行,所以①错误.

②根据线面平行的性质可知,平行于同一直线的两个平面不一定平行,也可能相交.所以②错误.

③若过平面外两点的直线与平面α相交,则无法作出平面和α平行,所以③错误.

④根据面面平行的性质可知平行于同一个平面的两个平面平行,所以④正确.

故答案为:①②③.

阅读理解

阅读理解。

      One day when Jack was walking in the park, he saw a woman, who lived a few miles away, sitting on a

bench with a dog beside her. The dog was looking up at the woman.

      Jack walked up to the woman and said, "Hello, Sue, how are you? May I sit and talk with you for a while?"

"Of course, Please sit down", Sue said. Jack sat down next to Sue on the bench, and they talked quietly together.

The dog continued to look up at Sue, as if waiting to be fed.

      "That's a nice dog, isn't it he?" Jack said, pointing at the animal.

      "Yes, he is. He's handsome. He's a bit of a mixture, but that's not a bad thing. He's strong and healthy."

      "And hungry," Jack said, "He hasn't taken his eyes off you. He thinks you've got some food for him."

      "That's true," Sue said, "But I haven't." 

      They both laughed and then Jack said, "Does your dog bite?"

      "No," Sue said, "He's never bitten anyone. He's always gentle and friendly."

      Hearing this, Jack decided to hold out his hand and touched the animal's head. Suddenly it jumped up and

bit him.

      "Hey!" Jack shouted. "You said your dog didn't bite." Sue replied in surprise. "Yeah, I did. But this is not my

dog. My dog's at home."

1. The dog looked at the woman because _______. [ ]

A. the woman wanted to feed him

B. the woman was friendly

C. he was strong and healthy

D. he was hungry

2. Jack and Sue were _______. [ ]

A. friends

B. nest-door neighbors

C. strangers

D. in the same family

3. Jack touched the dog because he believed _________. [ ]

A. the dog was handsome

B. Sue's dog was unfriendly

C. the dog belonged to Sue

D. Sue's dog was at home

4. We can infer from the passage that _______.[ ]

A. Sue gave a wrong answer

B. Jack made a mistake

C. the dog wasn't dangerous

D. both Jack and Sue like the dog

5. Which of the following can be the best title of the passage? [ ]

A. A Wrong Question

B. Sue's Dog

C. A Pleasant Meeting

D. Sue's Friend

单项选择题