放射工作人员防止眼晶状体发生非随机性效应的年剂量当量限值是（）

A.每年50mSv

B.每年150mSv

C.每年100mSv

D.每年250mSv

E.每年350mSv

Directions:

The following picture stands for Chinese Young Volunteers. Write an essay of 160～200 words based on this sign. Your composition should include.

1) description of the sign;

2) reasons why people want to volunteer, and

3) your comments.