选择最佳应答语( )
A:You are right.
B:No,we can't.
C:Not yet.
Be quiet. I can’t _______ the teacher.
已知数列{an}为等比数列,满足a4+a7=2,a2•a9=﹣8,则a1+a13的值为( )
南亚主要的气候类型及特点是( )