16、The balls are solid, makes them very heavy.
A.it B.what C.which D.that
17、Is this calculator you borrowed from Jane?
A.which B.one C.the one D.what
18、The scientist and his achievements you told me about are admired by us.
A.who B.that C.which D. /
19、I suppose the theory he stuck correct.
A.to prove B.to proving C.to proved D.prove
20、He is working hard, will make him pass the final exam.
A.who B.that C.which D.it
16、C 17、C 18、B
19、C 20、C