Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct
answer to each of the questions.
One of the most important discoveries of the nineteenth century was a method of using natural gas for cooking
and heating. Large amounts of natural gas are found in the United States, usually several feet below the surface
of the earth. Natural gas is most often found in places where petroleum, the oil from which gasoline is made, is
found. Often the natural gas must be removed before the oil itself can be reached.
For many years after natural gas was first discovered, it was thought to have no value. Finally, however,
people began to understand its use and to find ways of storing it and moving it from place to place. Today natural
gas is stored in large tanks and used for lighting, cooking and heating. It has also been used for electric generators
and hybrid cars recently. In many ways natural gas is one of our finest fuels. It can be used for cooking without
making the room hot. It is cheap and can be moved easily from one place to another through long pipelines, some
of which are hundreds of miles in length.
Question 38: What does the word "It" in the passage refer to?
A natural gas
B. electric generator
Question 39: This passage as a whole is about
A. discovering natural gas
C. finding petroleum
C. tank
B. natural
D. pipeline
gas and its use
D. using natural gas and petroleum