-- Excuse me, sir, smoking in the gas station.-- Oh, I'm really sorry.A. doesn't allow B. isn't allowed C. aren't allowed
-How long may I_______ this book? -For about a week.
-Ann is in hospital. -Oh, really? I_______ know. I_______ her for a long time.
It_______ ten years since Professor Du last_______ to the earth.
Mike's father_______ to London last month. He_______ there three times.
He used ____on the right in China, but he soon was used____on the left in England.