合成纤维中吸湿性最好的是()。
A.腈纶
B.维纶
C.氨纶
D.丙纶
参考答案:B
—What do you think Lucy will be _________ five years?
—I think she will be a doctor.
A.after
B.in
C.for
D.at
P型半导体是靠()导电。
A.离子
B.电子
C.空穴