A:His ideas may sound crazy
B:As his ideas may sound crazy
C:Crazy as his ideas may sound
D:As crazy his ideas may sound
有些同学知道上课时间用手机上网对学习影响很大,但总是不由自主。你的做法是 ( )①以坚强意志抵制不良诱惑 ②坚决不带手机到课堂,避开诱因
③培养学习兴趣,联想长时间上网的危害 ④请老师同学帮忙监督
求证 x2+y2 + x2+(1−y)2 + (1−x)2+y2 + (1−x)2+(1−y)2 ≥2 2 ,并求使等号成立的条件.