题干
— ________ does it take Bob to get to his grandparents' home?
— An hour.
A：How
B：When
C：How far
D：How long
答案(点此获取答案解析）
D
— ________ does it take Bob to get to his grandparents' home?
— An hour.
A：How
B：When
C：How far
D：How long
