Ex.8
Put the correct noun form of the underlined verb in the gap to completPut the correct noun form of the underlined verb in the gap to complete the definitions.
1.If you invent something important , this __ may become famous .
2.Something that arrives , such as a plane flight , is an __ .
3. You can say you improve something, or that you make an___ to it.
4.Something you publish , such as book or a magazine is a ___.
5.If you explain something clearly , then you are giving a clear ___.6. Someone who trains people to do something as a ___.

Ex.9

Write similar definitions to the ones in exercise 8 to explain the following verbs and nouns.
1. believe and belief
_______________________
2. depart and departure 
_______________________
3. perform and perfomance
_______________________