Reading passages

49- The points put forward in the lecture “ The Terror of Change” ............. .
A) are, for the most part, accepted
B) have changed scholars from a sense of optimism to one of gloom
C) hadn’t been considered by scholars previously
D) caused much debate and disagreement
E) filled several volumes
50- According to the writer, having no equivalents in the past, ............ .
A) analyses formulated by experts are open to discussion
B) books on the world’s problems cause a great deal of debate
C) Their World megacities are not sufficiently aided
D) Modern technological developments do not meet the needs of the people
E) today’s problems require new solutions
51- The outlook for the world’s future............. .
A) arouses optimism in some experts, yet pessimism in others
B) is a repetition of events which occurred in the past
C) depends entirely on technological advances made today
D) is one of overpopulation, pollution and reduced farm production
E) shows that the population will soon exceed the earth’s capacity

Iron has been known since prehistoric times. Although how humans first learned to extract the element from its ores is still debated, it is fairly certain that earliest, highly prized samples of iron were obtained from meteors. Several references to “the metal of heaven “ –most probably iron –have been found in ancient writings. By about 1200 BC. Iron was being obtained from its ores; this achievement marked the beginning of the Iron Age. Even with the development of other elements, iron and its alloys remain important in the economies of modern countries.

52- According to the passage, iron ............. .
A) is a very recent discovery
B) was discovered at the beginning of the Iron Age
C) was first obtained from a source other than iron ore
D) was the most important discovery in humans history
E) was not known until 1200 BC