盛装过易燃或有毒介质的容器，未经清洗处理，能否直接焊接？

填写单词：根据句子意思，在空格中填写适当的单词，使句子完整、正确。

1. Mary was born in 1994. So she is _________ years old now.

2. Yao Ming is one of the most famous _________ players in NBA.

3. There are twelve ________ in a year.

4. I hope my dream of university will come _________ soon.

5. No one taught him English. He learnt it by _________.

6. The heavy earthquake _________ in Wenchuan on May 12th last year.

7. Would you mind __________ the window? It's raining outside.

8. It's ___________ for the teenagers to swim in the river in summer.

简述炉管结焦的原因。

下列细胞核中所含遗传物质为2N的细胞有（）。

A.精原细胞

B.初级精母细胞

C.次级精母细胞

D.精子细胞

E.精子

由业主聘请管理承包商作为业主代表或业主的延伸，对项目进行集成化管理的模式是指( )。

A．BOT模式

B．EPC模式

C．PM模式

D．PMC模式

使用变速器（）时，即使离合器接合，发动机动力也不能传给驱动轮。

A.一挡

B.倒挡

C.空挡

D.超速挡