题目

Toys Anno… The world’s smallest, but the most beautiful exhibition space for old-day toys. Opening hours Monday—Friday: 10a.m.—6p.m. Sunday:9a.m.—1p.m. National Museum, London Bus 26/91/206 FREE service for all young people aged 8-16 ●Homework staff(工作人员) on hand to help you ●Space to work ●Books ＆ revision guides ●FREE Internet use ●FREE printing Manchester Library＆Information Service Escape(逃脱) from the Mummy’s Tomb!    Let our new online game take you to an old Egyptian tomb(埃及古墓).    Become a brave explorer and collect wonderful thing 基因A、a和基因B、b分别位于不同对的同源染色体上，一个亲本与基因型为aabb的个体测交，子代基因型为AaBb和Aabb，分离比为1∶1，则这个亲本基因型为 [　　] A． AABb B． AaBb C． AAbb D． AaBB