问题

Scientists are warning that ________ emissions of carbon (碳排放) are cut, we could be heading for an environmental disaster

A:before
B:as
C:unless
D:in case

正确答案是：

同类题型

I didn’t have to work all weekend — I did it by_______

I’ll come to see your performance at 9:00 tomorrow evening.— But by then my performance will have ended and I reporters in the meeting room at that time

Dogs are too _____ to take care of.

I really appreciate _____to relax with you on this nice island. [ ]

You can only be sure of ____ you have at present; you cannot be sure of something ____ you might get in the future.