81. Leptin functions ____.

1. to restrain us from gaining weight
2. to regulate our metabolism
3. to suppress our appetite
4. all of the above

82. The original function of Leptin, according to the passage ____.

1. can be maintained intact
2. can be regulated at will
3. can be suppressed
4. can be distorted

83. It is hypothetical that the rats fed on a bumper diet ____.

1. can boost their appetite by increasing the activity of Leptin gene in fat cells
2. can counteract their biological evolution
3. can inhibit their mechanism responsible for quelling appetite
4. can slow the production of Leptin

84. Rossetti would say that the similar mechanism in humans can trap overeaters in vicious spiral of excess ____.

1. unless they can accumulate reserve in their bodies
2. so that they eat better than before
3. where there is a scarcity of food
4. when food is plenty

85. The passage tells us that Flier argues that Rossetti's findings ____.

1. were convincing enough to be duplicated among moderately overweight people
2. cannot be repeated among moderately overweight people
3. merit further investigation
4. were fabricated

(Reference keys.)