She likes ______________ to work.[ ]
A. walking
B. walk
C. walks
答案:A
导致老年人骨质疏松的主要原因是人体骨骼缺少下列元素中的[ ]
A. Ca
B. Na
C. Fe
D. K
Not until ____________ to the top of the palace __________ caught.
A.he got; was he
B.did he get; he was
C.he got; he was
D.did he got; was he