Question

summarize it!
drag and drop the words or phrases that accurately complete the paragraph.
scientists have recognized the enormous sizes of and distances between objects in space. they have come up with units of
that would communicate the relative sizes and relative distances of these
bodies. relative
refers to how big the planets are when compared to each other and the sun. relative
refers to how far apart the planets are when compared to each other and the sun.
astronomical light year astronomical unit distance
universe size measurement galaxy

Explanation:

• "units of measurement" is a common phrase for units used to quantify things.
• "celestial bodies" (though not in the options, but the context implies space - related bodies like planets, Sun etc. which are celestial). Since the options have no "celestial", but the first blank is about units for quantifying (measurement), second about space - related bodies (though the best fit from options is not perfect, but considering the context of space objects, we proceed).
• "relative size" is about how big objects are compared (as per the text "how big the planets are...").
• "relative distance" is about how far apart (as per "how far apart the planets are...").

Answer:

measurement, (assuming the second blank is about space - related bodies, but since "celestial" is not an option, but the context is space, we can think of the general term for space objects), size, distance.