题目

某生物兴趣小组抽样调查的200人中，各种基因型和人数情况如下表所示，则这200人中，Xb的基因频率为 基因型XBXBXBXbXbXbXBYXbY 人数781487030 A.85% B.30% C.20% D.15% 答案：CThe course about Chinese food attracts over 100 students per year，________up to half are from overseas.A．in which B．for whomC．with which D．of whom