In the following passages the numbered gaps indicate missing words. Against each number in the below each passage, five choices are offered in columns lettered A to E. For each question choose the word that is the most suitable to fill the numbered gap in the passage. Locusts have from time to time been the cause of terrible -71- of farms. -72- of locusts can, in a few hours, strip vast areas of green and fertile country of all signs of -73-. They are -74- or periodic -75-. After a heavy -76- of an area, they may not reappear for ten or fourteen years. Now that more is known of the life of locusts, there periodic -77- are better understood and consequently more -78-. Scientists now know the regions in which the gregarious phase of locusts may occur, and can even sometimes -79- when an -80- will take place. By modern methods of dusting and -81- the young locusts, such as the -82- can be destroyed on a large -83- before they do much -84-. The D.DT -85- has proved particularly effective. The main source of -86- to the government is -87-, which can be direct. While the former is based on one's -88- the latter is imposed on goods and -89- and is paid only when these are -90-. Other sources include -91-, such as those paid by mining companies, and sale of -92- for dogs, guns, hotels e.t.c. Another major source is -93-, which is different from others because it has to be repaid. From these and other sources, government is able to raise -94- with which it carries out its -95- which include administration and the -96- of services. Besides, it is able to control the country's -97- by imposing taxes sometimes to prevent -98- or by altering patterns of -99- through the raising of -100- against certain foreign products.
In question numbered 81 above, choose the best option from letters A - E that best completes the gap.
A. wiping B. pumping C. disposal D. draining E. spraying
