题干
I got close enough to hear them speaking Chinese, and I said “Ni Hao ” just as I ____ do in China.
A：must
B：might
C：can
D：should
答案(点此获取答案解析）
B
中，若记位于第i行第j列的数为aij（i，j=1，2，…，n），则当n=9时，表中所有满足2i＜j的aij的和为