以下哪些不适宜进行PTA治疗？（） A.长段血管完全闭塞，但流出道通畅 B.大动脉炎

阅读理解。

Dear Editor (编辑),

     After I finish my homework, I often go online and chat with my friends and play Internet games. But

my parents hate to see me playing games on the computer. Maybe they have heard too much news about

how QQ and Internet games harm (伤害) children. Once I went to a net bar (网吧) to play games after

school. But after that I told my parents that I was playing basketball at school. I said so because I didn't

want to make them unhappy. I feel bad about it. However, I need to rest for a while by playing computer

games after studying for a long time. I really want my parents to understand that. Do foreign parents do

the same to their children? Please help me.

                                                                                                                                      Yours,  

                                                                                                                                       Li Ping  

Dear Li Ping,

     I think it's not strange for parents to keep their children away from anything bad. Foreign parents will

do the same as your parents! They may not let their children watch TV for a long time, or like your

parents, they don't want their children to play computer games.

     Talk to your parents and be honest (诚实) to them, I think. Tell them what you are doing and why

you are doing so to make them understand you. It's never good to do things behind your parents' backs.

They aren't fools as you think sometimes! Our parents seem to know what is the best for us. Remember:

to be honest is the best way. 

     Good luck!

                                                                                                                                        Yours,  

                                                                                                                                         Zhang Yu

根据短文内容，选择最佳答案。

1. From the passage we can learn that Li Ping often ________.

A. talks to his friends on the Internet    

B. plays basketball after school

C. plays computer games at home  

D. chats online before doing his homework

2. The boy goes online ________.

A. to get news about QQ              

B. just to have a rest

C. to show that he hates study          

D. just to find some friends

3. The underlined (划线的) sentence in Letter Two means "________".

A. You must do everything in front of your parents

B. You must always listen to your parents carefully

C. You should tell your parents what you do before or after doing it

D. You should not do anything to make your parents worry about you

4. The editor thinks ________.

A. children should play computer games secretly

B. playing computer games can be very helpful to children's studies

C. children should be honest and try to make their parents understand them

D. foreign parents don't care for their children as much as Chinese parents

燃烧性取决于烟叶的化学成分，物理特性及燃烧区内空气流通程度。包括（）、（）、（）、（）、燃烧后的灰色及密结性六个方面。

绘一幅某市市区交通旅游图，用下列哪一个比例尺较为合适（　　）

A．1：10000

B．

C．

D．图上1厘米代表实地距离50千米

反循环替泥浆施工时，接好进、出口管线，（）装单流阀。

A、进口需要

B、出口需要

C、进、出口都需要

D、进、出口都不需要

体内合成胆固醇的直接原料是（）。

A.丙酮酸

B.苹果酸

C.乙酰辅酶A

D.草酸

E.α-酮戊二酸