《曹刿论战》中曹刿认为"可以一战"的条件是什么?____,____,____。
— It is too noisy here. I can’t stand it.
— Me, too. We have to________ new ways to solve the problem.
如果(x+a)(x+b)的结果中不含x的一次项,那么a、b满足( )