In the following passage, at certain points you are given a choice of three words, one of which fits the meaning of the passage. Choose the best word.
One of the most interesting new books published recently is "Spaceship' by Prof. E.C. Walker, Our earth he says 1. (a) is (b) have been (c) will be like a spaceship, and all the 400 million people 2. (a) over (b) on (c) upon earth are passengers on it. And we are heading 3. (a) about (b) to (c) towards a disaster. The levels of atmospheric pollution 4. (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 5. (a) in (b) of (c) for the whole planet. If this rose a few 6. (a) degrees (b) steps (c) miles the deserts of the world would expand to double their size. The polar ice caps would start inching. If the polar ice caps melted, the 7. (a) water (b) ice (c) sea level all over the world would rise 8. (a) in (b) by (c) to about 60 meters. Prof. Walker's 9. (a) idea (b) thought (c) book is not at all about gloom and doom. He admits that the 10. (a) ideas (b) changes (c) solutions he describes could take thousands of years.