基因型为AaBb(两对基因自由组合)的某种动物,可以产生下图中各种基因型的子细胞。请回答:
过程③和④代表的变异分别是()、()。
参考答案:基因突变;染色体变异
Was it _____ he was playing volleyball on the playground _____ he got hurt? [ ]
A. that; when
B. when; that
C. that; where
D. where; that
旧的构件代号和平法构件代号,哪种可用,哪种已经过时了?