Answer:
A.
Explanation:
high mountains and plateaus
The correct answer is: Russia (although big parts of Russia are not in Eastern Europe but in Asia.
Russia has a huge territory which is generally very empty, especially in the North, where the conditions are harsh -there are only 150 million people in Russia, 10 million of which live in or near Moscow.
Earth is a terrestrial planet.
I believe the correct term to fill the blank in the statement is a tiltmeter. Geologists use a tiltmeter to measure the tilting of the ground along a fault. This instrument is designed to measure small changes from the vertical level of the ground or any structure.