When Mr. Lee came to life, he found himself lying on the floor with his hands _____ behind his back.
| A．tying | B．to be tied |
| C．tied | D．having tied |
We must take measures to stop various kinds of pollution ______ the environment gets worse.
| A．unless | B．until |
| C．before | D．when |
The rumor has been confirmed __________ UN peacekeeping forces would take operations in the region .
| A．what | B．why | C．that | D．how |
Hearing his friend calling him , out __________ .
| A．rushing the boy | B．the boy was rushing |
| C．rushed the boy | D．did the boy rush |
Whatever happens, you may depend on ________ that I will be with you.
| A．it | B．/ |
| C．what | D．that |
__________ in the new on-line game , he missed the final boarding call of his flight .
| A．Absorbed | B．Absorbing |
| C．Having absorbed | D．Being absorbed |