In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

[Q]: The term " epidemiology " appears to have first been used to describe the study of epidemics in 1802 by the Spanish physician Villalba in " Epidemiologi ́ a Espan ̃ ola " .
[A]: The term ' epidemiology ' was first used in 1802 by the Spanish physician Villalba .


[Q]: Several radioactive substances are considered carcinogens , but their carcinogenic activity is attributed to the radiation , for example gamma rays and alpha particles , which they emit .
[A]: The carcinogens in them are caused by the radiation they release , such as gamma rays or alpha particles .


[Q]: He was replaced by General Henry G. Winkelman who decided that in the north the Grebbe Line would be the main defence line where the decisive battle was to be waged , partly because it would there be easier to break out with a counteroffensive if the conditions were favourable .
[A]:
He was replaced by General Henry G. Winkelman who decided that in the north the Grebbe Line would be where the battle was to be fought , partly because it would be easier to counterattack .