相关系数的计算公式是（）。 A.A B.B C.C D.D

证明：32不可能写成n个连续自然数的和．

男性患儿，6个月，发热、呕吐、抽搐1天来诊

经各项检查，初步考虑为化脓性脑膜炎，对诊断最有意义的检查是（）。

A.血象

B.血培养

C.脑电图检查

D.脑脊液检查

E.头部CT检查

高效范围是液力变矩器的重要评价参数，其含义是（）之比。

A、最大力矩与最小力矩

B、最大转速与最小转速

C、最大功率与最小功率

D、最大效率与最小效率

Directions: Read the following passage. Answer the questions according to the information given in the

passage and the required words limit.

     Even plant can run a fever, especially when they're under attack by insects or disease. But unlike human,

plants can have their temperature taken from 3,000 feet away straight up. A decade ago, adopting the infrared

(红外线) scanning technology developed for military purposes and other satellites, physicist Stephen Paley

came up with a quick way to take the temperature of crops to determine which ones are under stress. The

goal was to let farmers precisely target pesticide (杀虫剂) spraying rather than rain poison on a whole field,

which invariably includes plants that don't have pest (害虫) problems.

     Even better, Paley's Remote Scanning Services Company could detect crop problems before they became

visible to the eye. Mounted on a plane flown at 3,000 feet at night, an infrared scanner measured the heat sent

out by crops. The data were transformed into a color-coded map showing where plants were running "fevers".

Farmers could then spot-spray, using 50 to 70 percent less pesticide that they otherwise would.

     The bad news is that Paley's company closed down in 1984, after only three years. Farmers resisted the

new technology and long-term backers were hard to find. But with the renewed concern about pesticides on

produce, and refinements (改进) ininfrared scanning, Paley hopes to get back into operation. Agriculture

experts have no doubt the technology works."This technique can be used on 75 percent of agricultural land

in the United States," says George Oerther of Texas A& M, who recently retired from the Department of

Agriculture, thinks remote infrared crop scanning could be adopted by the end of the decade. But only if Paley

finds the financial backing which he failed to obtain 10 years ago.

1. In what situation will plants have a fever? (No more than 8 words)

    ________________________________________________________________________________________

2. How can we apply pesticide spraying precisely? (No more than 10 words)

    ________________________________________________________________________________________

3. Why may infrared scanning technology by brought back into operation? (No more than 13 words)

    ________________________________________________________________________________________

4. What is the biggest problem that might prevent bringing infrared scanning technology back? (No more than

    7 words)

    ________________________________________________________________________________________

所有的科学事实都必须基于（）

A.理论

B.前人的结果

C.客观的证据

D.假设