---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.

---- Oh, dear! She _______ a lot of difficulties!

A．may go through

B．might go through

C．ought to have gone through

D．must have gone through

如图所示，小华在探究液体内部压强的特点时，将压强计的探头放入水中某一深度处，记下U型管两边液面的高度差h，下列做法能够使高度差h减小的是

A．将探头向上移动一段距离

B．将探头向下移动一段距离

C．将探头放在食盐水中的同样深度处

D．将探头在原深度处向其他方向任意转动一个角度