环境空气中不应含有腐蚀性和易燃性按气体及导电尘埃，特种电梯工作环境中腐蚀性和易燃性气体及导电尘埃不应超过该电梯额定指标。()
参考答案：对
根据句意和中文注释，写出所给单词的适当形式。
1. It is very important for children to learn to be ________(诚实的).
2. Don't leave the child ________(by oneself) near the river. It's dangerous.
3. It is a________(not useful)book.so I throw it away.
4. I couldn't ________(相信) my eyes when he came to my home.
5. The Greens will have a ________(令人愉快的) trip because they plan everything carefully.
下列药物可以治疗男性早泄的是（）
A.抗抑郁药
B.α-受体阻滞剂
C.5α-还原酶抑制剂
D.抗胆碱药
E.5-磷酸二脂酶抑制剂
)book.so I throw it away.