A:炙手可热
B:不孚众望
C:层出不穷
D:众矢之的
________a clever boy! ( )
-- Can you see the seeds? -- No, they are the ground.
用手将一重为5N的物体全部压入水中,物体排开的水重8N,此时物体受到的浮力为 ____N,放手后物体将 ____(填“上浮”或“下沉”),待物体静止时所受浮力为 ____ N.