The correct answer is:
<span>(4) military authorities considered them a threat to national security.
Many of them (around 60 percent) were born in the US and no longer had any contact to Japan, and some didn't even speak Japanese, yet they were considered a threat (unjustly).
</span>
<span> a means of rewarding the Duke of Marlborough</span>
It showed everyone inventions were imporant, it also made work so much easier instead of having to carry things, you could just use the pulley which was less strain on the human body and less chance someone could get hurt.
