[名词解释] 测交种(test cross variety)
[名词解释] 交叉 crossing
[单选题]通过测交,不能推测被测个体()A . 是否是纯合子B . 产生配子的比例C . 基因型D . 产生配子的数量
[单选题]—I always look out before crossing the street.—You are right. You can't be too______.A. nervousB. carefulC. carelessD. hurried
[名词解释] 跨线设备 track-crossing facilities