Only when it is hungry ______ a human being.
| A．a lion will attack | B．a lion should attack |
| C．will a lion attack | D．should a lion attack |
—It______________to plant trees and grass on the hillside.
—Yes. They help stop soil from being washed away.
| A．makes sense | B．makes money |
| C．makes a living | D．makes a mistakes |
They’ve finally decided to put an end to the long and bitter________between them and make peace.
| A．survey | B．conflict | C．concern | D．request |
Stephen Hawking believes that the earth is unlikely to be the only planet_______life has developed gradually.
| A．that | B．where | C．which | D．whose |
Between the two generations, it is often not their age, _________their education that causes misunderstanding.
| A．like | B．as | C． or | D．but |
—Ken has gone to the Africa country to work as a volunteer.
— I would rather he _____there. The situation there is very tense.
| A．didn’t go | B．hadn’t gone |
| C．doesn’t go | D．hasn’t go |