his father has been to America twice 对twice 提问是真的，如果是上面那样，
问题描述：
his father has been to America twice 对twice 提问
是真的，如果是上面那样，
答
How many times has his father been to America ?
答
回答：How many times has his father been to America?
twice 是两次的意思 对次数提问要用How many times
应该不会吧,至少也有been吧!