Mr Lin, a famous writer, _______ our school last week.

The best way to prevent the air polluting _____ , but the sky is still not clear.

Unluckily, when I dropped in , Dr. Smith ____, so we only had time for a few words.

I noticed that my grandmother was very upset when I told her about the accident,so I wished I　　it to her.

--- We want to sit at the table near the window. --- I am sorry, but it _______ already.