题目内容:
The customs duties act _______ an essential leverage on regulating import and export behavior.
A.at
B.as
C.in
D.to
参考答案:【答案仅供学习,请勿对照自行用药等】
The customs duties act _______ an essential leverage on regulating import and export behavior.
A.at
B.as
C.in
D.to