53- The author is almost certain that ............. .
A) iron ore was the only known source of iron until 1200 BC
B) the best examples of iron work were produced during the Iron Age
C) the statement “the metal of heaven” in ancient writings refers to iron
D) modern industry couldn’t have developed without iron
E) how humans discovered iron ore will still be debated in the future
54- It is pointed out in the passage that ............. .
A) the method first used by man to extract iron from its ore is well known today
B) other materials have not completely replaced iron in modern times
C) meteors are still the primary source of iron
D) iron alloys are much less important in industry than pure iron
E) at no time has iron been considered as valuable as it is today
The question has often been asked why the Wright brothers were able to succeed in an effort in which so many others had failed. Many explanations have been offered but three reasons are most often cited. First, they were a team. Both men worked well together, read the same book, located and shared information, talked incessantly about the possibility of manned flight, and served as a consistent source of inspiration and encouragement to each others. They were also glider pilots. Unlike some other engineers who experimented with the theories of flight, Orville and Wilbur Wright experienced the practical side of their work by building and flying in kites and gliders. In addition, the Wright brothers had designed more effective wings for the aeroplane than had been previously engineered.
55- The experience distinguishing the Wright brothers from their competitors was that............ .
A) they were much cleverer than their contemporaries
B) their backgrounds were full of aviation successes
C) they had the chance to try their work ,being aviators
D) they were inspired by their masters who made experiments before
E) their erstwhile efforts were praised, which encouraged them to go ahead
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