Over the past decades, sea ice ______in the Arctic as a result of global warming.
| A．had decreased | B．decreased |
| C．has been decreasing | D．is decreasing |
The most important thing_____we should pay attention to is the first thing _____I have said.
| A．which; that |
| B．that; which |
| C．which; which |
| D．that; that |
The World Wide Fund for Nature is an organization_____aim is to protect wildlife.
| A．who | B．where | C．which | D．whose |
A container weighs more after air is put in,_____proves that air has weight.
| A．as | B．it | C．that | D．which |
I’ll take you to a shopping center nearby_____you may buy all_____you need.
| A．that; that |
| B．which; that |
| C．where; which |
| D．in which; 不填 |
Do you know the reason_____she didn’t attend her boyfriend’s birthday party yesterday?
| A．why | B．which | C．for that | D．for why |