The reason why the year consists of 365 days is because it takes 365 days for our planet to make one full revolution around the sun and the reason why the day consists of 24 hours is because it takes 24 hours for our planet to make one full rotation.
Geographycally speaking, Russia is situated North and West of China.
They are both countries which expand on a vast territory and confine with many countries:
China also confines with: North Korea on the East, Mongolia on the North, Kazakistan, Kirghizistan, Tagikistan, Afghanistan, Pakistan and India in the West, and Nepal, Bhutan, Myanmar, Laos and Vietnam in the South.
While Russia confines with: Kazakistan, Mongolia and Georgia on the South, Ucraina, Belarus, Latvia, Estonia and Finland on the West.
Answer: southern, southern has the most density.