He spent a large ___ of money on his books.

There is no doubt that all this puts a large _________ on a teacher with a large number of classes.

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

In the       of proof , the police could not take action against the man .

 ---What did our teacher do?---He raised his arm as a(n)        for us to stop.