在充满可燃气体的环境中，可以使用手动电动工具吗？为什么？

阅读理解。

     The  children  often  play  football  in the  garden  and  sometimes  break Mrs Smith's windows. One

afternoon Mrs Smith is at home and reads a book. In a minute she closes her eyes and goes to sleep. At

that time a little boy knocks (敲) at the door. Mrs Smith opens the door and asks, "Do you break my

window again?"

     "Oh, no," says the boy, "your window is open this time and my football is in your room. Can I get it

back, please?"

1. The children often go to the garden _____.

A. to play    

B. to fly kites    

C. to play football    

D. to play basketball

2. The children playing football often break Mrs Smith's_____.

A. doors    

B. windows    

C. books      

D. gardens

3. One afternoon Mrs Smith _____ at home.

A. is writing something

B. is cleaning windows

C. is watching TV

D. is reading

4. A little boy _____ Mrs Smith's door.

A. opens    

B. closes    

C. knocks at    

D. breaks

5. The children's football is _____.

A. in Mrs Smith's room  

B. in the garden

C. on the window          

D. Mrs Smith's

控制性详细规划的主要内容是( )。

A．确定城市的性质、规模、发展方向、对外交通、基础设施、道路系统、园林绿化以及新区开发、旧城改建的基本原则等

B．对城市土地利用、人口分布和公共设施、城市基础设施的配置等作出进一步安排

C．规定建设用地性质、土地使用强度、市政管线定位、空间环境的规划控制要求等

D．作出建筑、道路和绿地等的空间布局和客观规划设计，以及综合技术经济论证等

使用灵敏度试片时，可以获得和试件相等的灵敏度，而与其材质是否相同无关。

（）的可焊性差，通常不用它作为焊接结构。

风险自担，是指企业预留一笔风险金或随着生产经营的进行，有计划地计提资产减值等。 ( )