stand by 候选乘机
take up 开始做
tie us up 让我们有负担
by
in
up
1.by
2.up
3.up
1 Sometimes you can fly really cheaply if you stand by.
2 If you want to lose weight,you should take in a new sport.
3 We dicided to rent a flat.Buying a flat would tie us up too much right now.
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024