Which best summarizes what scientists learned about how microbes benefit the human body?
They are part of a normal human ecosystem.
They have become less harmful to humans than they used to be.
They help process nutrients, fight disease, and accommodate change.
They help humans overcome the effects of antibiotics.

I think the answer is "They help process nutrients, fight disease, and accommodate change." Am I sure? Nope. (I just passed the question)

Explanation:

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.

answer; collective security;