Answer:
Borders are imaginary lines that divide a nation, state, province or city from others. These dividing lines can be taken from geographic features, such as rivers, seas, lakes, mountains, etc .; or in geometric form, using lines as meridians and parallels; or for ethnic reasons, dividing populations based on languages, ethnic origin, etc.
Examples of each of these types of border are:
-Natural border between Argentina and Chile along the Andes Mountains, taking as the dividing line the highest point of the same.
-Geometric border between America and Canada on the west coast, taking the line of parallel 49 as division.
-Ethnic border between Pakistan and India, dividing both nations according to concepts of Islamic or Hindu religious affiliation.
If you could dig a tunnel right through the Earth you could theoretically free-fall to the centre of our planet in just eighteen minutes. You can’t, of course: such a tunnel would have to tolerate temperatures as high as the surface of the Sun and pressures three and a half million times greater than those at the Earth’s surface.
the answer here is Abyssal Pains
The correct answer is - 2. Earth's climates have changed and are likely to change in the future.
From what is known for the geologic past of the Earth, our planet's climate has been changing numerous times. The climate on the planet has varied from being predominantly wet tropical climate, to having ice ages, having multiple different climate types at the same time... The reasons for the changes in the Earth's climate are numerous, with the Sun's radiation, tectonic movements and activities, volcanic activity, outside influences like asteroid and meteorite collisions, the vegetation, and all of them have managed to create a very colorful climate history of the planet. This trend of climate change should continue in the future as well, as all of the aforementioned factors are still influencing the climate and on top of that the humans have become a factor in the climate change too.
