1. Roman physicians described the chills and fevers and recurring attacks of malaria, noting that it was most frequent in low, marshy areas.
    罗马时代的医生描述了疟疾患者的周期性寒热，指出它多发生在低洼沼泽地带。

2. Ross first wanted to answer the simple question whether plasmodium could be found in a mosquito after it had bitten a malaria-infected person.
    罗斯首先要回答在蚊子叮咬过被疟疾感染过的人后，会不会在蚊子体内发现疟原虫这一简单问题。

3. One of these, the bark of cinchona tree, was found to be excellent for treating malaria.
    其中，人们发现用金鸡纳树皮来治疗疟疾疗效极好。

4. Other tests were made, and it was at last established that plasmodium was in the blood of all individuals stricken with malaria.
    又做了一些其它的试验，最后终于确定，疟疾患者的血中都有疟原虫。

5. 1. People who slept out of doors were more likely to contract malaria than those who didn´t.
    1． 在户外睡觉的人比那些不在户外睡觉的人更容易感染疟疾。

6. If the term sounds unscientific to 20th-century ears, let us remember there is a definite connection between marshy lands and malaria, and that the naming of the disease itself perhaps represents a praiseworthy effort of observation.
    尽管对20世纪的人来说，“坏空气”一词听起来不科学，我们应该记得沼泽地和疟疾之间有着肯定的联系，因此，“坏空气”一词自身也许代表着一种值得称道的观察。

7. In 1883 an American physician, A.F.A.King, listed twenty observations which he believed pointed to mosquitoes as a factor in malaria.
    1883年，一位叫A. F. A. 金的美国内科医生列举了他所观察到的20种现象，说明蚊子极可能是产生疟疾的因素。

8. In the end the hypothesis that mosquitoes transmit malaria to human beings could be tested only by direct experiment — on man.
    最后，关于蚊子给人类传播疟疾的假设只有直接通过人来进行实验。