Directions.

A. Study the following picture carefully and write an essay of about 160--200 words.

B. Your essay must be written clearly on the ANSWER SHEET 2.

C. Your essay should meet the requirements below:

1) Describe the drawing,

2) interpret its meaning, and

3) point out its implications in our life.

裂解气压缩机各段出口温度控制在90℃左右时，就不会有烯烃聚合物的生成。