The medicine works more effectively_____you drink some hot water after taking it.
| A.as | B.until | C.although | D.if | 
Our English teacher requested that the homework __________ tomorrow morning.
| A.would be handed in | 
| B.be handed in | 
| C.hand in | 
| D.must be handed in | 
Don't respond to any e-mails __________ personal information, no matter how official they look.
| A.searching | 
| B.asking | 
| C.requesting | 
| D.questioning | 
-Oh, Mum, just a few minutes.
 -Hurry up, Harry. Or by the time you pack your belongings, the flight __________!
| A.has left | 
| B.will have left | 
| C.had left | 
| D.was leaving | 
__________ I see him, he looks sad.
| A.Every now and then | 
| B.Every now and again | 
| C.Every so often | 
| D.Every time | 
By the time you have finished this book, your meal __________ cold.
| A.gets | 
| B.has got | 
| C.will get | 
| D.is getting |