Thetimeandefforthehasdevotedduringthepastfewyears

問題詳情：

The time and effort he has devoted during the past few years _______ trees in that remote area is now considered to be of great value.

A. of planting    B. to plant   C. plant    D. to planting

【回答】

D

知識點：非謂語動詞

題型：選擇題