This factory produced much dirty water, which resulted in a wide _______ of environmental problems.
A.branch | B.range |
C.species | D.wave |
I don’t know who invented ________ telephone. It’s really ________ most useful invention.
A.the; a | B./; a | C.a; the | D./; the |
----Whose advice do you think I should take?
----________.
A.It doesn’t matter | B.That’s it | C.It’s up to you | D.Either is OK |
I know a little bit about the city as I __________ there for one year in my youth.
A.am studying | B.had studied | C.studied | D.have studied |
Leaves are found _______ all kinds of trees, but they differ greatly ________ size and shape.
A.in; on | B.in; from | C.on; by | D.on; in |
To save class time, our teacher has ________ students do half of the exercises in class and complete the other half for our homework.
A.we | B.us | C.our | D.ours |