1. mucus - a slimy substance produced in the nose and throat to moisten and protect them
2. sterile - free from germs
3. enables - gives ability, power, or means to; makes able
4. specialize - to develop in a special way
5. critical - being important to the outcome of a situation
For #6-10, the word in italics is the one most similar to the first word.
6. scarce | plenty | many | rare
7. critical | important | useful | relaxed
8. sterile | dirty | germ-free | bacteria
9. enables | teaches | makes empty | allows
10. specialize | stretch | adapt | organize
I can't help you with the last one, because that's specific to you. If you have questions on how to work on that one specifically, though, feel free to message me or post a question about it. :)