随着钢的含碳量的增加，其强度也将随着（）。

A.下降；

B.提高；

C.不变；

D.不一定变;

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.