我国旅游业的主要国际客源地区依次排列的正确顺序是()。
A、大洋洲
B、亚洲
C、欧洲
D、美洲
参考答案:B, C, D
I ________ through that bitter period without your generous help.(2011·陕西)
A.couldn't have gone
B.didn't go
C.wouldn't go
D.hadn't gone
咳声不扬者,属于什么?