Nowadays people are more concerned about the environment________they live.
| A．what | B．which | C．when | D．where |
the project as planned, we’ll have to work two more hours a day.
| A．To complete | B．Complete | C．Completing | D．Completed |
You don’t need to make fancy foods to impress guests—it is something simple but good _____ will do.
| A．what | B．that | C．which | D．who |
The school has developed an online systemstudents can choose their own teachers.
| A．which | B．that | C．whom | D．where |
We’d better stay here a little longerhe turns up unexpectedly.
| A．although | B．in case | C．since | D．if only |
---I’m sorry, but there is no smoking on this flight.
---Oh, I _____that. Sorry, I won’t again.
A. don’t know B didn’t know C. won’t know D. haven’t known