You should never base anything on a theory that _________ impractical in practice.  
#86010
A
is proved
B
prove
C
proves
D
proved
推荐题目
More than one child _____to the cave to see the strange animal.
#85655
A
have gone
B
are gone
C
has been
D
is been
----______ he have a tennis ball ?  ---- No, he _________.
#43717
A
Do; doesn’t
B
Does; do
C
Does; doesn’t
D
does; does