______ the local authorities put more attention to the safety of the children, more than 20 lives __________ in Gansu Province.

A．Should, would not be claimed

B．Had, would not have been claimed

C．Should, would not be cost

D．Had, would not have been cost

可诱发人或哺乳动物皮肤癌的物质是　　

A．石棉

B．煤焦油

C．双氯甲醚

D．亚硝酸盐

E．黄曲霉毒素