题干
—Your T-shirt is nice. It must be expensive.
—Not at all. I only spend $10 it.
A：in
B：on
C：for
D：of
答案(点此获取答案解析）
B
—Your T-shirt is nice. It must be expensive.
—Not at all. I only spend $10 it.
A：in
B：on
C：for
D：of
的常数项是第
项；②
的前
；③
展开式中
的正指数项的系数之和大于
的常数项是
其中正确命题的个数为( )
