居民委员会是基层群众性自治组织，没有行政强制权力，其开展工作所依靠的方法是( )

现在中挡的数控系统仍多采用RS-232串行接口方式与上位机通信（）

Ma Lili’s parents are going to give a birthday party for her. She’s going to be fourteen years old. Ma Lili has a lot of friends. They are going to come to the party. They are girls from Ma Lili’s school. There are twenty-five of them.

Ma Lili’s mother is making birthday cakes for the party. They are very nice cakes. Ma Lili says to her mother, “Mum, you’re very nice. Thank you for your nice cakes. ” Her father is going shopping. He buys a lot of apples, bananas, oranges and pears.

It’s four o’clock in the afternoon. Now everything is ready. The party begins in thirty minutes.

1. Who is going to give Ma Lili a birthday party?

A. Ma Lili    B. Her friends   C. Her teacher   D. Her parents

2. How many people are coming to Ma Lili’s party?

A. Two      B. Twenty      C. Twenty-one     D. Twenty-five

3. Her mother _____ for her party.

A. is making cakes   B. is shopping   C. is buying apples   D. makes a cake

4. How old is Ma Lili going to be?

A. 12      B. 13      C. 14       D. 20

5. What time does the party begin?

A. At four                  B. At half past four

C. After five o’clock     D. At about six o’clock

1 5个月的小儿用药剂量为成人的

A．1/18～1/14

B．1/14～1/7

C．1/7～1/5

D．1/5～1/4

E．1/4～1/3

人类区别于动物的最主要的特征是

A．能形成条件反射
B．有第一信号系统
C．有学习记忆能力
D．有第一和第二信号系统
E．对环境适应能力大

道岔与曲线之间的直线段长度有何规定？