对那个小男孩来说，草为什么是绿的曾经是个谜。
A: The reason which the grass is green was once a mysterious to the little boy.
B: The reason why the grass is green was once a mystery to the little boy.
C: The cause that the grass is green was once a mystery to the little boy.
D: The cause which the grass is green was once a mysterious to the little boy.
A: The reason which the grass is green was once a mysterious to the little boy.
B: The reason why the grass is green was once a mystery to the little boy.
C: The cause that the grass is green was once a mystery to the little boy.
D: The cause which the grass is green was once a mysterious to the little boy.
举一反三
- There was once a little boy who dreamed of ______ around the world.
- Patches of green had begun to appear. There was green grass ________.
- One boy is a boy, two boys half a boy, three boys no boy.
- We arrived at a farmhouse, in front of ___ sat a little boy. A: it B: that C: which
- Where is the missing boy is still a _______. A: mystery B: mysterious