Answer:
At this very moment, the International Space Station orbits Earth at a distance of 240 miles.
Step-by-step explanation:
We use the simple present tense when we talk about actions that happen often, habitual actions, or truths that usually do not change or that take some time to change. For example: I sleep at 10 in the evening. / Dogs bark and birds fly. / Dora lives in Spain.
Therefore, since the orbit of the International Space Station is a truth that will most likely take long to change, it seems best to use the simple present to complete the sentence. Since the subject is third-person singular, we must add -s to the verb:
- At this very moment, the International Space Station orbits Earth at a distance of 240 miles.
Note: Another possibility would be the use of the present continuous: "is orbiting". However, that makes it seem this is just a temporary action that will, at any moment, change.