题目

（·湖南省长沙市一中高三上第二次月考） His silence at the meeting suggested that he _________ with you. A. didn’t agree                 B. hadn’t agreed       C. wouldn’t agree               D. shouldn’t agree 答案：A下列求导正确的个数是（   ）①（3x）′=3x·ln3　②（2+sinx+ex）′=cosx+ex③（+cosx）′=+sinx④（）′=A.1                              B.2                              C.3                              D.4