单项选择题
According to this passage（）
A．one can choose his color preference B．one is born with his color preference C．one’s color preference is changeable D．one has to choose his favorite color as soon as he can see clearly
单项选择题 Many people who first visit the United States will find that（）
单项选择题 In the first paragraph, Mark thought that（）
单项选择题 21（）
