A survey of the opinions of the students _______ that two hours of physical exercise a day _______ acceptable in our campus.
A:shows; are
B:shows; is
C:show; is
D:show; are
已知2a=3b=m,ab≠0且a,ab,b成等差数列,则m=( )
下列各操作中,一定能使不饱和溶液变为饱和溶液的是( )