Question

differentiating star systems
choose the word from the drop - down menu that completes each sentence.
a/an star system is made of two stars.
a/an star system is made of no more than a few thousand stars.
a/an star system is made of more than a million stars.

Explanation:

Binary star systems have two stars. Open clusters have up to a few thousand stars. Globular clusters have over a million stars.

Answer:

1. Binary
2. Open - cluster
3. Globular - cluster