Although James Cook　　　the first westerner to have discovered Australia,New Zealand and Hawaii,his travels led to the creation of more accurate and reliable maps for vast parts of the world.

--- Have you told him we have changed the plan?I _____ have, but I haven’t done it yet.

There was plenty of time. She ______ .

No student      go out of school after eleven o’clock at night without the teacher’s permission.

I can hear the Browns' phone bell ringing but no one is answering it; they _______ be at home.