It is obvious that water is to be _____to the development of life.
| A．gentle | B．fundamental | C．harmful | D．fierce |
Suddenly I heard a man shouting at a driver, ________ car was blocking the street.
| A．which | B．whose |
| C．of whom | D．of which |
After visiting Harbin, most of the foreign friends said they would never forget the time ________ they had spent.
| A．that | B．what |
| C．when | D．at which |
Eleven people got killed in the accident, ________ the identities haven't been available.
| A．whose | B．of whom |
| C．to whom | D．with whom |
It's said to be a case of murder ________ the children were used by adults.
| A．when | B．where |
| C．which | D．that |
Naturally a smile ________ the eyes participate is extremely communicative.
| A．to which | B．in which |
| C．at which | D．with which |