Human facial expression differ from those of animals in the degree _______ they can be controlled on purpose.
问题描述：
Human facial expression differ from those of animals in the degree _______ they can be controlled on purpose.
A.with which B.to which C.of which D.for which
请说明原因（degree、extent都用to?类似搭配还有么?）
答
B.to which
to the degree 表示所能达到的程度
这里先行词是degree,后面就是把介词提前到which前面,the degree to which .
to the degree,to the extent 所能达到的程度
to some degree/ extent 在某种程度上
to a certain degree/ extent 在一定程度上