问题补充:
. The concert was a great success--there wasn’t a single empty seat in the concert hall, it was very cold.
A. because
B. when
C. unless
D. although
答案:
A. because
B. when
C. unless
(答案→)D. although
解析:本题的含义是这场音乐会很成功,虽然天气很寒冷,但在音乐会大厅没有一个空位,although表示虽然的意思,故本题选D。