酒精中毒常导致哪族维生素缺乏
A．D族
B．B族
C．E族
D．C族
E．K族
参考答案：B
Listen! Some birds are singing __ the tree!
A．in
B．on
C．at
D．of
The rain is very heavy, _____ we have to stay at home. [ ]
A. but
B. because
C. so
