Question

fill up) 1the main elements present in the earth's core are___and___
2-the source of sun's immense energy is the conversion of_____into_____
3-one cannot hear sound on the ____ due to absence of the air
4-____was the first aircraft to reach the moon
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Answer 1

Answer:

1. The main elements present in the earth's core are iron and nickel.

2. The source of the sun's immense energy is the conversion of nuclear energy to solar energy.

3. One cannot hear sound in the space due to absence of the air.

4. Luna 1 was the first aircraft to reach the moon.

(Not that sure about the second item, since the source of the sun's energy is from nuclear fusion)