---Mum, I’m going to visit my aunt. What about a week? ---A week is too long. Try to be back in ____of days.

She is in a poor ______of health,which worries her mother much.

We all know that our teachers have different _______of teaching

I listened to Dr. Johnson’s lecture about biology, but I failed to get its key ____.

____ in the area reported _____ three people robbing the bank with their heads wrapped in stocks.