The teacher found difficult to decide he would take with him to attend the conference.A.

问题补充：

The teacher found difficult to decide he would take with him to attend the conference.

A. it; whom

B. himself; who

C. this; whom

D. that; who

答案：

A. it; whom

B. himself; who

C. this; whom

D. that; who

解析：第一空用形式宾语it,第二空可以用who或whom引导宾语从句并在从句中作take的宾语。