题型:名词解释 下列命题:①设a,b是非零实数,若a<b,则ab2<a2b;②若a<b<0,则1a>1b;③函数y=x2+3x2+2的最小值是2;④若x、y是正数,且1x+4y=1,则xy有最小值16.其中正确命题的序号是______. 查看答案
题型:名词解释 —What’s the weather like today?— . Good luck to you!A.It’s a fine day B.Be carefulC.I think so D.Good idea 查看答案