问答
51．The light bulb gives people more time___ every day．
52．You are not supposed t visit a friend's house without___first when you're in Switzerland．
53．Don't bring food to the classroom，or it___．
54．Mr King___ six countries over the years．
55．---Why are you still here？The movie was over fifteen minutes ago．
---Oh，I___ my wallet．
56．---Do you like the exhibition？
---The photos of th ecountryside are so great that they___me a lot．
57．Nancy shut the door and___the office．
