A:玉米粉和有氧
B:大豆粉和有氧
C:玉米粉和无氧
D:大豆粉和无氧
若二项式(x-2x )n的展开式的第5项是常数项,则正整数n的值为( )
-----______ there any living things on other planets ?
-----I have no ideas. Maybe we can know more about that in the future.