题目

31.一个基因型为YyRr的精原细胞和一个同样基因型的卵原细胞，按照自由组合定律遗传，各能产生几种类型的精子和卵细胞 A.2种和1种 B.4种和4种 C.4种和1种 D.2种和2种 答案：AThen arose the question _________ we were to get so much money.A．whereB．thatC．about whichD．in which