Условие:
Определите, какой из предложенных вариантов является эквивалентным, обращая внимание на функции слова «опе» («оnеs»). One should be very attentive when doing researches.
Doing researches requires careful attention on the part of the doer.
This research made one think they should be especially very attentive.
One of the main requirements to be observed when doing researches is attention.
