豚鼠毛色的遗传符合基因的自由组合定律，相关基因均位于常染色体上．毛色的产生机理为：白色前体物→棕色→黑色，其中A基因控制棕色，B基因控制黑色．另外基因d纯合会抑制色素的产生，但因其基因频率非常低，一般不予考虑．现有纯合的白色豚鼠和纯合的棕色豚鼠若干（未考虑d基因），请回答相关问题：

    Qian Xuesen was born in Hangzhou, Zhejiang Province on December 11,1911. After his graduation from Shanghai Jiao Tong University in 1934, he ____(旅行) across the Pacific Ocean to the United States for further study. There he received his degrees. After he graduated, he became a teacher as well as a researcher. He worked ____(努力地) and became a famous scientist.

    He ____(返回) to China in 1955. He played an important role in science in China. He was honored as “The Father of China's Missiles(导弹)”. He is the  ____(骄傲) of the Chinese people. He died on ____(十月) 31, 2009 at the age of 98, but he is a man who ____ (仍然)encourages Chinese young people. His love to his country was expressed in his saying, “My career(事业), my ____(成功) is in China and my destination is in China!” When someone said he could make much more money if he stayed in ____ (美国), he laughed and said, “My family name is Qian, but I don't like qian.”