WAEC - English Language (2019 - No. 62)
choose the word or group of words that best completes each of the following sentences:
The research was carried out _________a sample population.
over
in
with
on
توضیح
The preposition "on" is the most suitable choice in this context because when conducting research, we often say it is carried out "on" a sample population. This usage conveys the idea that the research is performed concerning or with regard to a specific group of individuals, which is the sample population. So, the complete sentence implies that the research was conducted with a focus on or involving a particular sample population.