Answer: What are you asking?
Explanation:
For example, oxygen is released by plants and humans relay it into carbon dioxide which gets turned back into oxygen
Answer:
I am not worried about the exam. I am strong enough to at least pass.
Explanation:
I believe you wanted a completion to the sentence? Either way don't worry about your exam, just do your best. But doing your best doesn't mean going "i'll do my best" and just hoping you know the answers. Go study! Now <em>that's </em>doing your best.
It depends, how you pronounce your name, if it is pronounced," key-ah-nah" than you use the 2nd one. If it is pronounced, "Cah-nah" than you use the first one
Hope this was help