16. These wild flowers are so special I would do ________ I can
to save them.
A. whatever B. that C. which D. whichever
17 I hate ____ when people talk with their mouths full.
A it
B this
C that
D them
18 A computer can only do ____ you have instructed it to do.
A what B
that
C how D which
19 The reason lies in ____ she works harder than the others do.
A that B how C it D what
20This is all ____our teacher
explained to us in class.
A. what B. that C. which D. of