1.Beijing is no longer _______it used to be before liberatio

1.Beijing is no longer _______it used to be before liberation.
A.that
B.where
C.how
D.what（正确）
2.the place_______interests the children most is the children's palace.
A.that（正确）
B.where
C.what
D.in which
3.Is this museum______ some foreign friends wisited that day?
A.where
B.which
C.that
D.the one（正确）