云南某地梯田规模巨大,级数最多的达5000级,现已成为中外闻名的观光景点。当初修建梯田的主要目的是[ ]
A、保持水土
B、发展旅游
C、利于浇灌
D、便于运输
答案:A
.
All the tickets have been sold out. ______ is left.
A.No one
B.Nothing
C.None
D.Not anyone