熏蒸剂类农药的杀虫机理是什么？

A. 正确
B. 错误

A. our production costs must be no more than 15 percent
B. has done damage to our reputation
C. to negotiate with you
D. to make this product possible

A. 记过
B. 留校察看
C. 警告
D. 开除学籍