-- is your birthday?
-- It's on March .
A:When; twenty ninth
B:When; twenty-nineth
C:What; twentieth-ninth
D:When; twenty-ninth
下列物质的用途中,利用其化学性质的是( )
(Ⅰ)证明:展开式中没有常数项;
(Ⅱ)求展开式中所有有理项.