— go out for a walk this evening?
— That's a good idea.
A:Let's
B:Why not
C:Shall we
D:What about
look like, clean the table, pick up rubbish, praise…for
设a=∫0πsinx+cosxdx,则二项ax-1x5式展开式中x2项的系数是( )
下列加线词在句中的解释正确的一项是()