Fill in the blank 68.

Directions: In the following passage, at certain points, you are given a choice of three words in brackets, one of which fits the blank. Choose the word which best fits the meaning of the passage and mark the corresponding letter viz. (a), (b) or (c) as your answer.

PASSAGE – I
One of the most interesting new books published recently is “Spaceship” by Prof. E.C. Walker.
Our earth he says 61. [(a) is, (b) have been, (c) will be] like a spaceship, and all the 400 million people 400 million people 62. [(a) over, (b) on, (c) upon] earth are passengers on it. And we are heading 63. [(a) about, (b) to, (c) towards] a disaster. The levels of atmospheric pollution 64. [(a) increasing, (b) arriving, (c) coming] in the cities and industrial areas of the world could in time change the weather patterns of the earth, raising the temperature 65. [(a) in, (b) of, (c) for] the whole planet. If this rose a few 66. [(a) degrees, (b) steps, (c) miles] the deserts of the world would expand to double their size. The polar ice caps would start melting. If the polar ice caps melted, the 67. [(a) water, (b) ice, (c) sea] level all over the world would rise 68. [(a) in, (b) by, (c) to] about 60 meters. Prof. Walker’s 69 [(a) idea, (b) thought, (c) book] is not at all about gloom and doom. He admits that the 70. [(a) ideas, (b) solutions, (c) changes] he describes could take thousands of years.