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．to plant           B．to planting            C．plant                D．planting

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.

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. plant        B. planting         C. to plant          D. to planting

The time and effort he has devoted during the past few years _____ trees in that village are now considered to be very important.

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

The time and effort he has devoted during the past few years _____ trees in that village are now considered to be very important.

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