Teachers have to constantly update their knowledge in order to maintain their professional ___.

On the top of Mount Tai，you can get a wonderful________of the sunrise.

There are ten＿＿＿teachers and two hundred＿＿＿students in the school．

“I don’t think it’s my _____ that the window has been broken. I just played football with my friends and John kicked the ball forwards the window.”said the boy.

一Let’s try operating the machine right now．一Wait．Better read the ______ first．