John, you ____ the computer game for two hours. It’s bad for your eyes. Stop, please! —OK, Mum.

I’m afraid I’m not _____to help with the talent show, for I am fully occupied with my own project.

Alice was playing in the park while I __________my homework at home.

I’m afraid I gave you a lot of trouble________ my stay here.

Do you know that a 13-year-old English boy has done a nuclear experiment successfully —_______ unusual work he has done!