选择合适的选项填空补全对话。 A. how B. how old C. how far D. how many E. how much F. what colour 1. — ____________ is his hair? — It is gray. 2. — ____________ is it from Beijing to Guangzhou? — It's about 6 thousand kilometres. 3. — ____________ is your father? — He is 40 years old. 4. — ____________ is this pair of the pants? — It's cheap, only ten yuan. 5. — ____________ glasses do you have? — I have only one. 6. — ____________ does your sister go to Beijing? — She takes a bus.