Answer:
Evolution is a scientific theory used by biologists. It explains how living things change over a long time, and how they have come to be the way they are. ... It is known that living things have changed over time, because their remains can be seen in the rocks. These remains are called 'fossils'.
a) A warm air mass rises above a cold air mass during a warm front, but two cold air masses surround a warm air mass during an occluded front.
