翻译：
By making vehicles lighter in weight aluminum has greatly reduced the amount of fuel needed to move them, (Passage Two)
.If you have really been studying English for so long, it’s about time you _____ able to write letters in English.
We can hear （）from the back of the room.
The back garden of our house contains a lawn ，（） very pleasant to sit on in summer.
What a nice day! How about the three of us _____ a walk in the park nearby.
