题目

Nina is clever but kind of lazy. If she _________harder, she _________ better grades.                              A. will work; gets     B. works; will get        C. will work; will get 答案：B解析:略化简：（1）﹣5a+（3a﹣2）﹣（3a﹣7）（2）3（8xy﹣3x2）﹣5xy﹣2（3xy﹣2x2）