题目

—Alice, you look puzzled．Have you understood it? —Yes, I         another problem just now. A．have thought of                                                                      B．am thinking of C．had thought of                                      D．was thinking of 答案：D决定化学反应速率的主要因素是w.w.w.k.s.5 u.c.o.mA. 反应物的浓度             B. 反应温度C. 使用催化剂               D. 反应物的性质