The answer to the missing blank above would be 'the Mongols'. The Mongols invaded Russia around 1300s, which arose to economic downfall and overall negative effect to Russia. Because of this, the Russian princes convened and fought to drive Mongols out of the country.
A globular cluster is a collection of stars in the form of a sphere that orbits a galactic core. Global clusters are generally tightly bound by gravity, making the stellar density higher toward the center, and giving them their spherical shapes. Globular clusters are usually found in the halo of a galaxy.
The fact that the gravitational pull of a globular cluster is rather weak means that a single supernova explosion can blow the interstellar gas out of a globular cluster. This would mean that the gas left is not dense enough to form new stars. After the first generation, globular clusters cease to form new stars because they lack material due to their deficiency in heavy elements.
Answer:
The purpose of the campaign was to reunify China
Explanation:
Unify the country and end the warlordism that typified China after the Xinhai Revolution.
Your answer would be volcanologist
