16. The relative abundance of dissolved salts in seawater in descending order is as follows
A. Chlorine, sodium, sulfate, magnesium, calcium, potassium
B. Sodium, chlorine, magnesium, potassium, sulfate, calcium
C. Chlorine, magnesium, calcium, sodium, potassium, sulfate
D. Chlorine, sodium, magnesium, calcium, potassium, sulfate
17. The planets with no natural satellites (reported so far) are
A. Mercury and Venus
B. Earth and Pluto
C. Mars and Neptune
D. Jupiter and Saturn
18. The percentage of the incident radiation reflected back to space is called
A. Planet’s albedo
B. Earth’s albedo
C. Both are similar terms
D. None of the above
19. The plants of which of the following crops are highly sensitive to frost?
A. Barely
B. Cotton
C. Maize
D. None of the above
20. The religion of Afghanistan is
A. Islam
B. Buddhism
C. Hinduism
D. Christianity