Reading passages

317 -According to the passage, hydrocarbons are ---- .
A) chemical elements classed as impurities
B) chemical compounds consisting of carbon and hydrogen
C) trace elements that give petroleum products their individual characteristics
D) refined using a complex system of distillation
E) found in compounds in small quantities
318 -Petroleum products vary so much in physical appearance because --- .
A) impurities change the nature of the substance so much
B) there is a great' demand for them in different forms
C) their chemical composition is made up of countless elements -
D) carbon and hydrogen atoms can join in thousands of different ways
E) trace elements have a remarkable effect on hydrocarbons

There is an advantage to launching satellites from the equator. The Earth spins faster there, giving rockets a boost in reaching orbit that allows them to carry heavier payloads. But there are few suitable launching sites on the equator that would not involve political problems. Therefore, an international consortium has converted an oil - drilling platform into a floating launch pad, rocket

assembly plant, and mission control. They hope to develop the capacity to launch commercial telecommunications satellites.
319 -The main advantage of launching satellites from the equator is that ---- .
A) it is easier to put larger satellites into orbit from there
B) it does not cause political problems in the countries concerned
C) there are a number of oil -drilling platforms available in the area
D) the weather is more reliable there
E) life is cheaper for the mission control and rocket assembly staff
320 -The passage states that an international consortium ----- .
A) is planning to launch satellites from the equator
B) has had problems as to the use of the oil - drilling platform in the equator
C) is negotiating with the equatorial countries for a launching pad
D) is ignoring the political problems having arisen in the area
E) is temporarily launching satellites from an oil - drilling platform