（ 表示氯原子， 表示氧原子， 表示氢原子）

下列说法正确的是（   ）

阅读短文，下列问题

B

    Andy plays basketball for the children's basketball club. He usually gets up at around 5:30 and runs in his school from 5:40 to 6:40. After running, he has breakfast at 7 o'clock. For breakfast, he eats some eggs and vegetables. At around 8:00, he plays basketball with his friends. They play basketball for around four hours. At about 12:00, they have lunch. For lunch, Andy has lots of vegetables, chicken and fruit. At 3 o'clock in the afternoon, Andy goes to the children's basketball club. He is never late for the club. Then Andy has dinner at about 7:00. After dinner, he watches basketball games on TV. Andy usually goes to bed at 10:30.

若用玉米作实验材料验证孟德尔分离定律，下列因素对得出正确实验结论影响最小的是（　　）

这样一则民间故事：一对夫妇晚年得子，十分高兴，把儿子视为掌上明珠，捧在手上怕飞了，含在口里怕化了，儿子长大以后什么事都不让他干，连基本的生活也不能自理。一天，夫妇俩要出远门，怕儿子饿了，于是想了一个办法，烙了一张大饼，套在儿子的颈上，告诉他想吃时就咬一口。但是等他们回到家里，儿子还是饿死了。原来他只知道吃颈前面的饼，不知道把后面的饼转过来吃。