If nothing________，the oceans will turn into fish deserts.
| A．does | B．had been done |
| C．will do | D．is done |
He was ________and died of lung cancer at an early age.
| A．addicted to smoke | B．addictive to smoke |
| C．addicted to smoking | D．addictive to smoking |
The girl ________at the party yesterday is missing today.
| A．referring to | B．refer to | C．referred to | D．to refer to |
Mary got up early________ she could prepare breakfast for her brother.
| A．so that | B．although | C．as if | D．even if |
The teacher told him to speak louder ________by everybody.
| A．so as to be heard | B．so as to hear |
| C．in order that heard | D．in order to hear |
Everyone here will thank the firefighters for the things they did to prevent fires ________the environment safer.
| A．to make | B．make | C．making | D．from making |