16.He ____ to sing in the next room a moment ago.A.heard B.was hearing C.had heard D.was he

16.He ____ to sing in the next room a moment ago.A.heard B.was hearing C.had heard D.was he
16.He ____ to sing in the next room a moment ago.
A.heard B.was hearing C.had heard D.was heard
17.A neighbour helped to keep our dog.It _______ while we were on holiday.
A.was taken care B.took care of
C.is taken care of D.was taken care of
18.About 500 cars ______ in the factory next year.
A.were produced B.will produce C.have been produced D.will be produced
19.Green trees and colourful flowers could everywhere in Guangzhou.So the people also call Guangzhou “Flower City”.
A.see B.be looked C.are seen D.be seen
20.Was the picture _______the teacher yesterday
A.shown B.show C.shown to D.show to
21.The boy was made ____ streets without pay in the old days.
A.to clean B.clean C.cleaned D.be cleaned