There are about 4, but I think the most important are~
To persuade and to inform.
Well it matters what the definition is because their are two definitions of entreated.
Upside and downside can mean a positive and a negative aspect of something, respectively. However, none of the options here present a couple of something negative and something positive: so I think we need to use the local meaning. So our analogy is:
on one extreme of some location (on the upper side): on the other extreme.
Therefore the best other couple is outside and inside: they also show two opposite locations.
The answer for this question would be B) indirect or the second option.
The answer is A. In the early years of the space program, astronauts studied three complex subjects: rocket engines, flight mechanics, and computer theory.
