生活污水管道一般采用()。
A.铸铁管
B.塑料管
C.混凝土管
D.带釉陶土管
E.钢管
参考答案:A, B
-Shall we go and have a picnic at the weekend?
—________ It is said there might be snow then.
A.Why not?
B.It sounds great!
C.Well, I can’t agree with you more.
D.That depends.
影响潮间带生物最重要的生态因素是什么?