—The supermarket is crowded(拥挤的). There are ___________ people there.—Yeah, and the things there are always ______________ expensive(贵的).
A:too much; much too
B:much too; to many
C:too many; much too
D:many too; too much
等比数列{an}的前n项和Sn,且a3=32,S3=92,求an的表达式.
请用“>”“<”或“=”连接:
①合金中所含铁元素的质量分数:生铁____ 钢;
②等质量的金属和足量的稀硫酸反应,生成氢气的质量:镁____铁;
③在空气中生锈的速度:用蒸溜水浸过的细铁丝____ 用食盐浸过的细铁丝.
不等式|x﹣1|+|x+2|≤4的解集是( )