① ____;
② ____.
把2x2﹣4x分解因式,结果正确的是( )
不等号填空:若a<b<0,则﹣a5____ ﹣b5;1a____ 1b;2a﹣1____ 2b﹣1.
—I've got a headache.
—No wonder.You in front of the computer too long.