题目

 With an online course Lynn has over 300, 000 students all over China ________her class    through the Internet. A. attending                  B. attended            C. attend                      D. are attending 答案：A我国有文字可考的历史源自 [     ]A．甲骨文B．铭文C．大篆D．二里头遗址陶器上的符号