Tu Youyou was ________ the 2011 Lasker clinical Medical Research Award on September 12 because she discovered a drug called artemisinin ________ against malaria.
A.presented;using | B.presented;used |
C.present;to use | D.presenting;used |
Don't handle the vase as if it ______ made of steel.
A.is | B.were | C.has been | D.had been |
Do you think this skirt is too tight ______ the shoulders?
A.at | B.on | C.to | D.across |
Wethe difficulty together, but why didn't you tell me?
A. | should face | B. | might face |
C. | could have faced | D. | must have faced |
Birds' singing is sometimes a warning to other birds ______ away.
A.to stay | B.staying | C.stayed | D.stayed |
______ at the door before you enter my room, please.
A.Knock | B.Knocking | C.Knocked | D.To knock |