20- The Berbers and the Arabs of the Sahara …….. . A) have established major settlements there
B) moved to the area in fairly recent times
C) fight over the right to settle in oasis areas
D) inhabit most areas of the Sahara desert
E) have not settled In the desert but moved around
21- We can assume from the passage that the Sahara may prove useful in the future because…… . A) It is growing and expanding towards the south
B) there are large amounts of necessary minerals there
C) it may be uniting with Nigeria and other countries
D) it may be used to irrigate neighbouring countries
E) it will probably continue to remain uninhabited
Relativity is the name for two theories of physics presented by Albert Einstein in 1905 and 1915
respectively, as the Special and General Theories of Relativity. Through them he showed that speed
and position are relative things and that there are no absolute measurements for time and space. He
also stated that matter and energy are interchangeable, a concept that has had considerable bearing on
the development of nuclear physics. In this century, Einstein's Theories of Relativity have
revolutionised ideas about the nature of matter and the universe, as Sir Isaac Newton's laws of gravity
had done to scientific thinking two centuries earlier.
22- According to the passage, Einstein's theories state that…………. . A) there are no definite ways to determine time or location
B) things can be measured by either special or general means
C) how fast something goes, and where it is, are fixed values
D) before 1905, scientists looked at the universe in the wrong way
E) there's simply no point in worrying about either time or space
23- As stated in the passage, Einstein claimed that…………. . A) matter and energy are really exactly the same thing
B) nobody really knows the true nature of matter
C) nuclear energy is definitely the best form of energy
D) the true nature of energy doesn‘t really matter
