The problem is not ____ so easy as you think. It’s far from being settled.

Mrs Black isn’t in and I’ll have to ring ______. I would appreciate it if you ring _____ after 6 o'clock?  

 The students are ___ young people between the ages at between the age of sixteen and twenty.

Our bodies are strengthened by taking exercise,______ our minds developed by learning.

Government officials cannot ________ accept bribes(受贿)，but in China quite a few take advantage of their power to break the rule .