Large animals that inhabit the desert have evolved a number of adaptations for reducing the effects of extreme heat. One adaptation is to be light in color, to reflect other than absorb the sun’s rays. Desert mammals also depart 62. ______ from the normal mammalian practice of maintaining a continuous body 63. ______ temperature. Instead of trying to keep down the body temperature deep inside the body, and which would involve the expenditure of water and energy, desert 64. ______ mammals allow their temperatures to rise to what would normally be fever height, and the temperature as high as 46 degrees Celsius have been measured 65. ______ in Grant’s gazelles. The overheated body then cools down during the cold desert night, and indeed the temperature may fall usually low by dawn, as low as 34 degrees Celsius in the camel. This is the advantage since the heat of 66. ______ the first few hours of daylight is absorbed in warming up the body, and an excessive buildup of heat does begin until well into the day. 67. ______ Another strategy for large desert animals is to tolerate the loss of body water to a place that would be fatal for nonadapted animals. The camel can 68. ______ lose up to 30% of its body weight as water without harm to itself, when 69. ______ human beings die after losing only 12% to 13% of their body weight. An equally important adaptation is the ability to replenish (补充) this water loss for one drink. The tolerance of water is of obvious advantage in desert, as 70. ______ animals do not have to remain near a water hole but can obtain food by grazed in 71. ______ sparse and far-firing pastures.