The new technology，if ________ to farming，will help increase the grain output.
| A．applying | B．to apply |
| C．applied | D．having applied |
What ________ pity that you couldn’t be there to receive ________ prize.
| A．a; a | B．the; a | C．a; the | D．the; the |
The pen, _____ I paid 2 dollars, was lost.
| A．to which | B．for which | C．which | D．that |
He was very rude to the Customs officer, _____ of course made things even worse.
| A．who | B．whom | C．that | D．which |
. China has hundreds of islands, _____ is Taiwan.
| A．the largest of which | B．of which largest |
| C．which the largest | D．in which the largest |
We travelled together as far as Chicago, _____ we said goodbye to each other.
| A．which | B．when | C．why | D．where |