Complete the sentences with the words below.

Write one word in each gap.

illusion, process, head, details, test, opinion

We need to stop working. Colin's [ ] is aching, he has to visit the doctor.

If I don't pass a difficult [ ], I will have to leave school.

Not everything that you see is true. It can be just an optical [ ].

I can't agree with you, because I've got a completely different [ ]!

Passing university entry exams is a complicated [ ].

You don't have to write about lots of unimportant [ ] in your essay.