Gases take up a lot of space because
a. they have weak chemical bonds.
b. their molecules have very little attraction for one another.
c. they contain very few atoms.
d. they have a small molar mass.

the correct answers are:

a - pacific plate;

it is the biggest oceanic tectonic plate. surrounded on all sides by continental tectonic plates, it is submerging and gradually becoming smaller and smaller.

b - north american plate;

huge continental plate, occupying big portion of the northern hemisphere.

c -eurasian plate;

alongside the north american plate, it is one of the two dominant continental plates in the northern hemisphere.

d - indian plate;

a small continental plate, that has been part of gondwanaland initially, but after the break up of it, moved towards northeast and pushed into the eurasian plate that was once part of laurasia.

if he does not use open the compass the a width greater than half of po, he will not be able to find the midpoint of the line, without the midpoint of the line, he will not be able to bisect the line.   to find the midpoint of a line the circles drawn with a compass must either intersect or be touching.