". VdoTips: general knowledge practice set



general knowledge practice set

16. For how many years have the dinosaurs been extinct?
(A) About 25 million years
(B) About 65 million years
(C) About 100 million years
(D) About 135 million years

17. A geostationary satellite revolves round the earth from
(A) East to West
(B) West to East
(C) North to South
(D) South to North

18.Among the following materials sound travels fastest in
(A) Steel
(B) Air
(C) Vaccum
(D) Water

19. The rear side of the moon was photographed by
(A) Viking I
(B) Viking II
(C) Luna III
(D) Mariner IX

20. Which phenomenon do bats or dolphins use to find prey, predators or obstacles?
(A) Refraction of sound
(B) Formation of beats
(C) Scattering of sound
(D) Echo location