Country which shares a border with the northernmost part of China : RUSSIA
Looking at the map I attached, you will notice that the northernmost part of China is to the North East between 120° E and 135° E. The country that borders this area is Russia.
Countries located between 105° E and 135° E lines of longitude:
Looking at the map and the lines of longitude circled, countries between these two lines of longitude are:
The Himalayan mountain range and Tibetan plateau have formed as a result of the collision between the Indian Plate and Eurasian Plate which began 50 million years ago and continues today. ... These scraped-off sediments are what now form the Himalayan mountain range.