A set of keys ____ in the library. Are they yours?
| A．is | B．am | C．are | D．aren’t |
—_____ the population of the U.S.A. in 2005?
—It _____ about 296 million.
A.What is; is B.What was; was
C.How many is; was D.How many was; is
—They have been to Australia.
—So _____ I.
| A．do | B．have been | C．did | D．have |
—Our school is beautiful!
—It will be more beautiful if more trees and grass _____ by us.
A. plant B. is planted C. are planted
—I have worked hard at math, but it seems that I haven’t made any progress.
—Keep on _____ at it, and you will be successful.
A. work B. working C. to work
—This physics problem is too difficult. Can you show me _____, Wang Li?
—Sure.
A. what to work it out B. what to work out it C. how to work it out