Everything is more modern now.
Always. Quadrilaterals are not always parallelograms, but parallelograms are defined as quadrilaterals with two sets of parallel sides.
Answer:
Because according to different family the needs of different family differ from each other
Permafrost refers to the fact that the ground in high latitudes which is permanently frozen - that is, which does not defreeze in the summer. It does not defreeze because it is isolated by soil - this is the correct answer - from the warmer air, so it is actually not in touch with the positive temperatures.