The what prevents food or liquids from getting into the lungs?

a)pharynx
b)larynx
c)alveoli
d)trachea

I think the correct answer from the choices listed above is option A. The pharynx is what prevents food or liquids from getting into the lungs. The pharynx is the throat  where food pass. There is a flap of cartilage that covers the windpipe (trachea) when swallowing occurs, preventing food and liquids from entering the trachea. 

16

Step-by-step explanation:

We must find integers x, y with the most amount of prime divisors, not necessarily distinct, such that x + 3y < 1,000.

Obviously, this is achieved when the divisor is the least prime 2. So, we must find integers n, m such that

 

since , then n must be 9. For n=9 we find the greatest integer m such that  

 

and we find m=7

 and   ,  are the numbers we are looking for and the sum of their length is 9+7 = 16.

So, 16 is the maximum possible sum of the length of x and the length of y.