Comets are basically dusty snowballs which orbit the Sun. They are made of ices, such as water, carbon dioxide, ammonia and methane, mixed with dust. These materials came from the time when the Solar System was formed. Comets have an icy center (nucleus) surrounded by a large cloud of gas and dust (called the coma).
Comets go around the Sun in a highly elliptical orbit. They can spend hundreds and thousands of years out in the depths of the solar system before they return to Sun at their perihelion. Like all orbiting bodies, comets follow Kepler's Laws - the closer they are to the Sun, the faster they move.
There are four general conditions that must be met for natural selection to occur, these are: variation among organisms of the same species, large production of offspring, variation in individual fitness among members of the same species and variation in heredity. So from the question given above, the conditions that are required for natural selection are option A, B AND D.
Answer:
B
Explanation:
Water, sunlight and amount of oxygen in water
<span>Thousands of years of isolation between tribal groups</span>
<span>when
the shoes floated low in the water,
while the ducks floated high in the water. The speed of the duck in water is
much faster than the shoes because the duck will overcome less resistance like
water current because it has lesser contact area. The shoes has greater probability
to change course because of larger contact area</span>
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