When ______ did you finish your homework last night?
A:in the earth
B:on the earth
C:in earth
D:on earth
明朝统治者加强君主专制的措施是( )
a、b是有理数,若ab>0,a+b>0,那么a、b的符号是( )
下列能直接体现我国精神文明建设的基础工程的是()