A:where
B:whe
C:that
D:in which
等比数列前n项和为54,前2n项和为60,则前3n项和为( )
已知集合A={y|y=|x|﹣1,x∈R},B={x|x≥2},则下列结论正确的是( )
⑴____ A. out B. shout C. house D. would
⑵____ A. tie B. big C. wish D. trick
⑶____ A. world B. important C. score D. more
⑷____ A. area B. bean C. cheap D. meat
⑸____ A. include B. number C. pumpkin D. fun
六年级进行计算比赛,共20题,规定算对一题得5分,错一题扣2分。晓华得了79分,他做对____ 题.