This is ______ key, and that is ________ orange. A. a; a B. a; an C. an; an
Don’t talk with your partners in class_______ you are asked to do so. A. ifB. whenC. unless
The volunteer spoke as clearly as she could_____________the visitors understand her. A. to makeB.makingC.made
--Is Jack in his room? ---No,I saw him _____ out with his backpack just now. A. go B. going C. went
.--- Cathy could swim when she was only 4 years old. ---_______________. A. So did Jack. B.So can Jack C. So could Jack
Waste water ____________________into Xiang River.It’s our duty to keep it clean. A. shouldn’t be poured B. mustn’t pour C. can’t pour