水溶性维生素的共同特点为()。
A.一般有前体物
B.不易吸收
C.会积蓄中毒
D.宜每日供给
E.以上都是
参考答案:D
The opening ceremony is to be held in the lecture hall this afternoon, _____ can seat 400 people.
A.where
B.when
C.that
D.which
经口明视气管插管术最关键是尽量显露声门。()