The moon orbits the earth at a mean distance approximately

A. 0.384 million km
B. 149.6 million km
C. 579 million km
D. 227.9 million km
✅ The correct answer is option A.
The moon orbits Earth at a mean distance of just over 384,000km. The moon’s orbit around Earth is also slightly eccentric – at perigee (its closest distance to Earth), it’s a little over 362,500km from Earth, while at apogee (furthest from Earth), it is almost 405,500km away.

The import of crude oil and petroleum done from national oil companies of producer countries, which have a net exportable surplus of oil is by

A. term contracts
B. term tenders
C. monthly tenders
D. All the above
✅ The correct answer is option A.
The import of crude oil and petroleum done from national oil companies of producer countries, which have a net exportable surplus of oil is by term contracts.

The relative abundance of dissolved salts in seawater in descending order is as follows

A. chlorine, sodium, sulphate, magnesium, calcium, potassium
B. sodium, chlorine, magnesium, potassium, sulphate, calcium
C. chlorine, magnesium, calcium, sodium, potassium, sulphate
D. chlorine, sodium, magnesium, calcium, potassium, sulphate
✅ The correct answer is option A.
The relative abundance of dissolved salts in seawater in descending order is chlorine, sodium, sulphate, magnesium, calcium, potassium.

The ocean water is saline due to

A. evaporation of its surface
B. volume of fresh water added by rainfall
C. salts are already present in sea water
D. both (a) and (b)
✅ The correct answer is option D.
Salt in the ocean comes from rocks on land. The rain that falls on the land contains some dissolved carbon dioxide from the surrounding air. This causes the rainwater to be slightly acidic due to carbonic acid (which forms from carbon dioxide and water).