In the corner of the room, we found the little boy ________ on the ground with both hands ______ up with a rope.

A．lying; tying

B．lying; tied

C．laying; tired

D．laid; tying

一个物体的体积为200cm³，将其体积的二分之一浸没在水中时，它受到的浮力是______N；全部浸没在水中时，被排开的水所受的重力是______N．