题目

请阅读下面内容，按照要求写一封书信。 Despite being asked to stay safe during the outbreak(爆发) of the novel coronavirus(新型冠状病毒), students and teachers across the country can keep themselves busy with classes online.A student used a mobile phone to attend an online class at home in the Inner Mongolia Autonomous Region in April. His home was recently connected to the Internet. DingTalk, a virtual workplace developed byAlibaba Group, held online classes for about 50 million students nationwide,from primary to high school level. Physics teacher Zhao Chuan下列各项中不属于无性生殖的是（　　）A．利用根繁殖B．利用茎繁殖C．利用叶繁殖D．利用种子繁殖