His sister since she left home in 1998.
| A．had not been returned | B．has not returned |
| C．had not returned | D．returned |
_____ unemployment and crime are high, it can be assumed that the latter is due to the former.
| A．Before | B．Where | C．Unless | D．Until |
It was a matter of________ would take the position.
| A．who | B．whoever | C．whom | D．whomever |
it rain tomorrow, we would have to call off the hike.
| A．Will | B．Would | C．Should | D．Were |
The government has decided to give preference to those environmently-friendly business and companies in all aspects in _______ of sustainable development.
| A．case | B．terms | C．honor | D．concerns |
The Voice of China is such a popular program with viewers has produced many a music-lover.
| A．who | B．that | C．where | D．as |