固定桥要求基牙牙根周围牙槽骨吸收不超过根长的().
A.1/2
B.2/3
C.1/3
D.1/4
E.以上都不是
参考答案:C
It's very bad for your ______ to read in the sun. [ ]
A. eyes
B. hands
C. arms
D. ears
It is still under discussion _____ the old bus station should be replaced with a modern hotel or not. [ ]
A. whether
B. when
C. which
D. where