题目

如果(a－b)2加上一个单项式便等于(a＋b)2，则这个单项式是（ * ） A、2ab      B、－2ab      C、4ab      D、－4ab 答案：CIt’s very________ that, in many schools, the students are going to spend less time in doing homework than they used to .A．possiblyB．probablyC．lovelyD．likely