North Sea is where large deposits of oil are located
Answer: 
Explanation:
We are asked to multiply 1 nano sec with 1 km/sec.
The conversion used from nano second to second
1 nsec = 
The conversion used from km to meters:
1 km = 1000 m

Putting the values we get:

Therefore, the given conversion is 
Answer:
The terrestrial planets are the inner planets that lie within the Asteroid belt. They have high densities compared to the Jovian planets and they are relatively smaller. They are comprised of silicate rocks and Carbon Dioxide, Oxygen, Nitrogen, and Argon are the gases found here. The density of Mercury, Venus, Earth, and Mars are 5.4 g/cm³, g/cm³, 5.5 g/cm³ and 3.9 g/cm³ respectively. Mercury and Venus are not rich in water, hydrogen, and helium gas because they might have evaporated or removed because they are nearest to the Sun.
Whereas Pluto is a dwarf, cold planet that lost its orbit and is at a great distance from the sun. It is beyond the planet Neptune and is no more considered as a planet of the solar system. A huge amount of ice is present here and comprised of gases such as Methane, Carbon Monoxide. It has a density of about 1.88 g/cm³, which is very less in comparison to the terrestrial planets.
The zone alog the southern margins of the sahara is called the SAHEL
Weathering is the mechanical and chemical hammer that breaks down and sculpts the rocks. Erosion transports the fragments away. Working together they create and reveal marvels of nature from tumbling boulders high in the mountains to sandstone arches in the parched desert to polished cliffs braced against violent seas.