填空题
从右栏所给选项中选出与左栏各项意义相符的选项。
51. It lets in light and air into the room. [A] boat
52. It is a road going over a river. [B] bridge
53. You walk on it in a room. [C] floor
54. You sit in it to travel across water. [D] street
55. You go into or out of a house through it. [E] window
[F] door
[G] garden