Answer

Answers to the fill in the blanks is as below:

1. makes -  (As this will have a simple present tense of the word due to the fact that it is a universal truth. Eg. The sun rises in the east.)

2. of - (Here, a conjunction would be best used)

3. Aren't  I - (Any interrogative sentence followed by an assertive positive tense     would be always negative)

4. didn't you -  (Any interrogative sentence followed by an assertive positive tense     would be always negative)

5. verb - (Grammatically, practice is a verb as it defines action. And Practise is a    noun.)

6. is going to rain - (tense used would be simple continuous tense as it is an         action happening in the current state)

7.inability - (ability and inability are antonyms. Ability: Capability to do some    thing; inability: No capability to do something)

8.forever - (Permanent and forever mean the same, that is some activity is              which is never going to end)

9.since - (Since is the best conjunction/helping word which can be used here)