The first English immigrants to that is (A) now the United States crossed (B) the Atlantic long after (C) Spanish colonies had been established (D) in Mexico, the west Indies and South America.

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  • s="" calculations="" go="" to="" the="" designer="" of="" part,="" and="" he="" must="" make="" it="" as="" strong="" stress="" man="" say="" is="" necessary.="" one="" or="" two="" samples="" are="" always="" tested="" prove="" that="" they="" intended.="" each="" separate="" part="" tested,="" then="" whole="" assembly="" —for="" example,="" a="" complete="" wing,="" finally="" airplane.="" when="" new="" type="" airplane="" made,="" normally="" only="" first="" three="" will="" be="" flown.="" destroyed="" on="" ground="" in="" structural="" tests.="" third="" air.When a plane has passed all the tests it can get a government certificate of airworthiness, without which it is illegal to fly, except for test flying.Making the working parts reliable is as difficult as making the structure strong enough. The flying controls, the electrical equipment, the fire precautions, etc. must not only be light in weight, but must work both at high altitudes where the temperature may be below freezing point and in the hot air of an airfield in the tropics.To solve all these problems the aircraft industry has a large number of research workers, with elaborate laboratories and test houses and new materials to give the best strength in relation to weight are constantly being tested.1.The two main requirements of aircraft design are ( ).2.The maximum possible weight of an aircraft is determined by ( ).3.The stress man's job is to ( ).4.The first three airplanes of a new type ( ).5.All equipment in an aircraft must( ).'>

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