对边平行且相等的四边形有______ A．长方形 B．正方形 C．三角形 D．平

阅读理解，选择正确的答案。

      My name is Mike. Tomorrow is the weekend. We have no classes. My parents aren't going to work, but

we are going to be very busy tomorrow. My mother is going to buy something for next week. My father is

going to visit my grandparents. I'm going to play football with my friends. Tomorrow evening, we are going

to have a big dinner. After that, I'm going to the cinema. I think we are going to have a nice weekend.

1. Mike has ____________ classes on the weekend.

A. 4

B. no

2. Mike's ____________ is going to visit Mike's grandparents.

A. father

B. mother

3. Mike is going to play ____________ with his friends. 

A. basketball

B. football

4. They are going to have a big ____________ tomorrow evening.

A. lunch

B. dinner

5. Mike is going to the ____________ tomorrow evening.

A. cinema

B. library

“七国之乱”

下列哪些措施可以增强北京的国际竞争力和服务功能①加大基础设施的建设力度②规划和建设重点功能区③建设城市快速轨道交通和高速公路④发展高新技术产业[ ]

A．①

B．①②

C．②③④

D．①②③④

心脏的正常起搏点是（）

A.窦房结

B.房室束

C.普肯耶纤维

D.左、右束支

E.房室结

根据《液压爬升模板工程技术规程》，爬模装置安装过程中，截面尺寸的允许偏差为（）mm。

A.±2

B.±3

C.3

D.±5