题目

You should have informed me that the lecture was canceled．I ________ all the way here through the heavy rain． A．needn’t have run                                        B．can’t have run C．shouldn’t have run                                    D．mustn’t have run 答案：A下列物质互为同系物的是A.葡萄糖和核糖(C5H10O5)B.麦芽糖和蔗糖C.硬脂酸和软脂酸D.乙二醇和甘油