Answer:
Oh I don't know what that is but good luck
Answer:
Even if a person doesn't show symptoms, they can still have it.
Step-by-step explanation:
That's the problem.
Even if you think everyone isn't sick, they very well could be, and because there is no vaccine and it spreads so quickly, there's a chance that all the people in that group could get it.
Answer:
First option: 
Second option: 
Fourth option: 
Step-by-step explanation:
Rewrite each equation in the form
and then use the Discriminant formula for each equation. This is:

1) For
:

Then:
Since
this equation has no real solutions, but has two complex solutions.
2) For
:

Then:
Since
this equation has no real solutions, but has two complex solutions.
3) For
:

Then:
Since
this equation has one real solution.
4) For
:
Then:
Since
, this equation has no real solutions, but has two complex solutions.