问题
______ riding shared bikes（共享单车）is an environmentally friendly way to travel，many of the bikes are thrown everywhere.
A:Although
B:As
C:Unless
D:Until;
B:As
C:Unless
D:Until;
正确答案是：
同类题型
The traffic is heavy these days. I ________ arrive a bit late, so could you save me a place?
A modern city has beenbuilt in______was a small fishing village.
There_______a talk show on CCTV-3 at eightthis evening.
It took _______ building supplies to construct these energy-saving housesIt took brains, too[ ]
I often get up at 6:00_______the morning and go to bed at 10:00_______night.