补充光照最好的方法是（）
A、早
B、晚
C、中午
D、早晚补充
参考答案：D
--- I don’t suppose the police know who did it.
--- Well, surprisingly they do. A man has been arrested and ____ now. [ ]
A. has been questioned
B. is being questioned
C. is questioning
D. has questioned
重为20N的物体，将其浸没在水中时，它排开的水重为25N，此时它受到的浮力为______N，松开手后物体将______（填“上浮”、“下沉”或“悬浮”）．
