为什么煤矿要制定灾害预防及处理计划？

阅读短文，完成各题。

      My name is Rose. I am 10 years old. My room is small and nice. There is a bed, a desk, a closet and

a shelf. The computer is on the desk. The books are on the shelf. The closet is behind the door. There is a

picture over the bed. I like my room very much.

1. Where are Rose's books?

    They are ___________ ___________ ___________.

2. Where is the closet?

    It is ___________ the door.

3. Is the picture over the bed?

___________________________________________

4. Her name is ___________.

5. Does she like her room?

___________________________________________

一辆长途汽车，在一条公路上单向直线行驶，以20 m/s速度行驶全程的，接着以30 m/s的速度行驶完其余的，求汽车在全程内的平均速度为___________m/s。

Are these your brothers?  _________

A．Yes, they re

B．No, they are

C．Yes, these are

D．Yes, they aren’t

下列说法不正确的是 （     ）

A．分子式为C₉H₁₀的含苯环的烯烃（不考虑立体异构）共有6种

B．芥子醇（）能发生氧化、取代、水解、加聚反应

C．实验室制乙烯时，把生成的气体通入酸性KMnO₄溶液，紫色褪去，不能说明一定生成了乙烯

D．将少量某物质的溶液滴加到新制银氨溶液中，水浴加热后有银镜生成，该物质不一定属于醛类

“粉301”是气焊（）用的焊粉。

A.紫铜

B.铝及铝合金

C.灰铁

D.不锈钢