更多"{{B}}Questions 29-30{{/B}}
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[填空题]{{B}}Questions 29-30{{/B}}
Which two people are most in favour of setting applicants problems
[填空题]{{B}}Questions 27-28{{/B}}
Which two people are most in favour of personality questionnaires
[简答题]Questions 11-22
Aviculturists, people who raise birds for commercial sale, have not yet learned
how to simulate the natural incubation of parrot eggs in the wild. They continue
to look for better ways to increase egg production and to improve chick survival rates.
line When parrots incubate their eggs in the wild, the temperature and humidity of the nest are controlled naturally. Heat is transferred from the bird’s skin to the top portionof the eggshell, leaving the sides and bottom of the egg at a cooler temperature. Thistemperature gradient may be vital to successful hatching. Nest construction cancontribute to this temperature gradient Nests of loosely arranged sticks, rocks, or dirtare cooler in temperature at the bottom where the egg contacts the nesting material.
Such nests also act as humidity regulators by allowing rain to drain into the bottomsections of the nest so that the eggs are not in direct contact with the water. As thewater that collects in the bottom of the nest
A. A．Nesting material varies according to theparrots’ environment.
B．Humidity is an important factor inincubating parrots’ eggs.
C．Aviculturists have constructed the idealnest box for parrots.
D．Wild parrots’ nests provide informationuseful for artificial incubation.
[单项选择]Snow
The two things m snow and mountains—which are needed for a ski area are the two things that cause avalanches, large mass of snow and ice crushing down the side of a mountain—often called "White Death."
It was the threat of the avalanche and its record as a killer of man in the western mountains that created the snow ranger. He first started on avalanche control work in the winter of 1937—1938 at Alta, Utah, in Wasatch National Forest.
This mountain valley was becoming well known to skiers. It was dangerous. In fact, more than 120 persons had lost their lives in 1936 and another 200 died in 1937 as a result of avalanches before it became a major ski area.
Thus, development of Alta and other major ski resorts in the west was dependent upon controlling the avalanche. The Forest Service set out to do it, and did, with its corps of snow rangers.
It takes many things to make a snow ranger. The snow ranger must be in excellent physical condition. He must b
A. a college graduate
B. a physicist
C. a geologist
D. a mountaineer
