【B2】A．toB．byC．forD．after

【C9】A．toB．ofC．forD．in

The question is still ______ discussion.A．inB．byC．forD．under

【C16】A．exposed toB．discovered byC．experimented byD．absorbed by

The making of the early mind of Richard Nixon owed most _____ his mother.A:toB:byC:forD

【C3】A．toB．aboutC．forD．with

【C9】A．toB．atC．forD．around