Erik remembered that his science teacher had told him that an explosion in space could not really be heard. Why
is this so?

Because space is a vacuum, gases released into space expand very quickly, and as they expand their density decreases. So say you were in a spaceship in the middle of a big space battle and a nearby ship exploded. The exploding ship would release gases and technically sound could travel along with them

Explanation:

answer; i believe the correct answer is (anemia);