I think the questions that must be ask are:
a.What does “encryption” mean?
d.What are “key distribution problems”?
All the text is based on the concept "encryption" so it is very important to know what it means in order to undestand the rest of the information. If not, you will be missing important facts. In addition, there are a lot of words used that are derived from this one, so you won't be able to undestand them.
Another important concept that gives a lot of information just by knowing it's meaning is "key distribution problems", they could be two or a thousand, it is important to know what they are and what they do.
The other question that seems important is the one of the "public key cryphtography" but this one can be inferred by the context.
<span>Wherever there is a doughnut shop, you will find a police car parked outside.</span>
Answer:
As soon as Shiro saw his master he ran to meet him, wagging his tail, and, seizing the end of his kimono, dragged him under a large yenoki tree. Here he began to dig very industriously with his paws, yelping with joy all the time. The old man, unable to understand what it all meant, stood looking on in bewilderment. But Shiro went on barking and digging with all his might.
Explanation:
I'm not too sure but the other parts in the story didn't seem like companionship to me, but in here the dog is helping the old man.
I know without a doubt that i should drink more water after exercising would most likely be your answer.