Reading and answers the question: While most desert animals will drink water if confronted with it,
for many of them the opportunity never comes. Yet all living things
must have water, or they will expire. The herbivores find it in desert
plants. The carnivores slake their thirst with the flesh and blood
5 of living prey. One of the most remarkable adjustments, however,
has been made by the tiny kangaroo rat, who not only lives without
drinking but subsists on a diet of dry seeds containing about 5%
free water. Like other animals, he has the ability to manufacture
water in his body by a metabolic conversion of carbohydrates. But
10 he is notable for the parsimony with which he conserves his small
supply by every possible means, expending only minuscule amounts
in his excreta and through evaporation from his respiratory tract.
Investigation into how the kangaroo rat can live without drinking
15 water has involved various experiments with these small animals.
Could kangaroo rats somehow store water in their bodies and slowly
utilize these resources in the long periods when no free water is
available from dew or rain? The simplest way to settle this question
was to determine the total water content in the animals to see if
20 it decreases as they are kept for long periods on a dry diet. If
they slowly use up their water, the body should become increasingly
dehydrated, and if they begin with a store of water, this should
be evident from an initial high water content. Results of such experiments
with kangaroo rats on dry diets for more than 7 weeks showed that
25 the rats maintained their body weight. There was no trend toward
a decrease in water content during the long period of water deprivation.
When the kangaroo rats were given free access to water, they did
not drink water. They did nibble on small pieces of watermelon, but
this did not change appreciably the water content in their bodies,
30 which remained at 66.3 to 67.2 during this period.
This is very close to the water content of dry-fed animals (66.5),
and the availability of free water, therefore, did not lead to any
"storage" that could be meaningful as a water reserve. This makes
35 it reasonable to conclude that physiological storage of water is
not a factor in the kangaroo rat's ability to live on dry food.1. What is the topic of this passage?
2. The word "expire" inline 3 is closest in meaning to
3. Which of the following is NOT a source of water for the desert animals?
4. The word "it" in line 3 refers to
5. The author states that the kangaroo rat is known for all of the following EXCEPT
6. The word "parsimony" in line 10 is closest in meaning to
7. It is implied by the author that desert animals can exist with little or no water because of
8. The word "deprivation" inline 26 is closest in meaning to
9. According to the passage, the results of the experiments with kangaroo rats showed that