English multiple-choice questions, simply say why you chose, the teacher wants the process and asks for help.

1 choose a to tell jokes: tell jokes b time depends on time, tell time c truth tell truth d lie.

Choose b to guide the absolute construction as the adverbial of the main clause without knocking at the door. Entering someone else's room is ambiguous, and the main sentence IT is a formal subject rather than a real infinitive as the subject. The word order of the original sentence is: it is ambiguous to enter someone else's room without knocking. It is impolite to enter other people's rooms without knocking.

Choose c, adjective discrimination as predicative, Abe is famous for ... Are you ready ... Have confidence in ...; Just relax。

If there is a problem with this question, you can use AC. A means you stayed in Canada 10 years, and c means you left Canada 10 years.

I hope I helped you.