题目

 –Do you know __________tomorrow? --At 8 o’clock. A. when did Sally come   B. when Sally came C. when will Sally come  D. when Sally will come 答案：D下列物质不属于天然高分子化合物的是（　　）A．淀粉B．蚕丝C．纤维素D．聚氯乙烯