A.浮力等于重力,一定悬浮
B.浮力等于重力,一定漂浮
C.物体在水中上浮,在没有露出水面之前浮力不变
D.在水中匀速下沉的物体重力大于浮力
答案:C
全口牙中体积最小的牙是 ()
A.上颌侧切牙
B.上颌第二双尖牙
C.下颌第一双尖牙
D.下颌第二双尖牙
E.下颌中切牙
There _______ a talk show on BTV-2 at eight last night.[ ]
A. is
B. was
C. will be
D. are