【单选题】
13.Oil floats if you ______it on water.
【单选题】
22. When a fire ______ at the National Exhibition in London, at least ten priceless paintings were completely destroyed.
【单选题】
23. Realizing that he hadnt enough money and ______ to borrow from his father, he decided to sell his watch.
【单选题】
20.The girl’s voice was so low that we could ________ hear her.
【单选题】
7.When we go abroad we are always being ______ around like a group of mentally disabled people.
【单选题】
9. All correspondence ______ to the editor should be sent by airmail.
【单选题】
11.Since family ______children’s character, he encouraged parents to teach children reading.
【单选题】
16.It was by train _____ we reached there.
【单选题】
17. It was the headmaster _____ gave us the leave to go to the concert.
【单选题】
15.It was on the day my first son was born _____ I put them in the soil.