-_______ can the batteries (电池) keep these cool iPhones and iPads working?
- For about ten hours.
| A．How much | B．How many |
| C．How long | D．How often |
---I hope you _______ my party next weekend?
--- OK, I _______ .
| A．to come in; will | B．come to; will |
| C．came: am | D．will come to; will |
I was doing my homework _______ mother was cooking.
| A．when | B．while | C．as | D．what time |
No one knows what _______ in fifty years.
| A．will our life be like | B．is our life like |
| C．our life will be like | D．our life is like |
If there aretrees, the air in our city will becleaner.
| A．less; more | B．more; more | C．more; much | D．much; more |
What _______ to her yesterday evening?
| A．was happened | B．happened | C．happening | D．happen |