481. what is the height of The atmosphere layer mesosphere?
A. 85 km
B. 50 km
C. 40 km
D. 10 km

482. Bromine is a___________________?
A. black solid
B. red-brown liquid
C. colourless gas
D. highly inflammable gas

483. The variety of coal in which the deposit contains recognizable traces of the original plant material is____________?
A. bitumen
B. anthracite
C. lignite
D. peat

484. The property of a substance to absorb moisture from the air on exposure is called____________?
A. osmosis
B. deliquescence
C. efflorescence
D. desiccation

485. An extremely small piece of silicon on which integrated circuits are implicated is called __________________?
A. Card Reader
B. Hollerith Code
C. Feed
D. Chip

486. Earth is closest to the sun every year in early ______________, when it’s winter for the Northern Hemisphere. We’re farthest away from the sun in early __________________, during our Northern Hemisphere summer.
A. January – July
B. June – December
C. July – January
D. December – June

487. What is it called when the Earth is closest to the sun _____________?
A. Aphelion
B. Perihelion
C. Apoapsis
D. Periapsis

488. Circadian Rhythm refers to _____________?
A. Planetary movements
B. Formation of galaxies
C. Human body cycles
D. Calisthenics

489. Fuzzy logic is a part of_________________?
A. Aristotle’s philosophy
B. Computer science
C. Epicurianism
D. Sophism

490. Periodontics deals with _____________?
A. Surgery of spine
B. Stomach disorders
C. Ligaments restoration
D. Dentistry
E. Heart attacks