Which country lies between china and russia?

There isn't a single country that lies entirely between China and Russia. However, several countries share borders with both China and Russia:

* Mongolia: This is the largest country that sits between China and Russia, sharing a significant border with both.

* Kazakhstan: Another large country that borders both China and Russia.

* Kyrgyzstan: This smaller country is nestled between China and Russia, sharing a relatively short border with both.

It's important to note that while these countries share borders with both China and Russia, they are not completely "in between" them. For example, parts of Kazakhstan extend beyond the line connecting China and Russia.