He had been having trouble （）a hotel room.A.reserving

He had been having trouble （）a hotel room.A.reserving
B.to reserve
C.reserved
D.reserve答案：A难度：1知识点：词汇与结构部分\辅导书\书A\结构A
A.reserving
B.to reserve
C.reserved
D.reserve
正确答案：A
解析:词汇与结构部分\辅导书\书A\结构A