在宏观、微观和符号之间建立联系是化学学科的特点。 （1）在水、铁和氯化钠三种物质

孙中山所说的社会革命的内容在辛亥以前指的是（）

对已充油的变压器、电抗器的微小渗漏进行补焊时，应保证变压器、电抗器的油面（）。

A.完全静止

B.温度在10至20摄氏度之间

C.呼吸畅通

D.呼吸闭锁

态氮（NO3-）进入植物体之后是怎样运输的？如何还原成氨（NH4+）的？

Directions :

Jordan is one of your business partners. Recently he was promoted to be the General Manager of ECC Company. Write a letter to

1) congratulate him on his promotion and

2) express your wish to cooperate with him.

You should write about 100 words on ANSWER SHEET 2. Do not sign your own name at the end of the letter. Use "Li Ming" instead. You don’ t have to write the address.

分割塔内的残液应排至（）。

A.轻污油系统

B.火炬系统

C.地下

D.燃料气系统