Answer:
First, rain will have to occur. The lake and surfaces will have water in them, after that it will a while for the surface to evaporate into water vapour, after that the water vapour will condense into water droplets and when the clouds are too heavy because of too much water droplets in them, it will start to rain again and this cycle will keep going on continuously.
I believe group of cells working together and or performing the same task can be categorized also as a specialized tissue.
20 is the Number of Neutrons of potassium.
The answer is Permian-Triassic extinction.
The Permian-Triassic extinction was 252 million years ago. It is known as The Great Dying because about 95% of all species died out due to environmental changes (volcanic eruptions, dry climate, melting of ice sheets, etc). This is also the only event in which many insect species wiped out.