The phrase "a main activity in" is correct and usable in written English.
It can be used to describe a significant or primary action or task within a specific context or field.
Example: "Research and development is a main activity in the technology sector."
Alternatives: "a primary task in" or "a key function in".
His main activity in the cistern is shooting arrows at a wooden dummy for hours that you can take without it being classified as theft.
The main activity in the anaerobic process is the creation of an antioxidant environment by anaerobic organisms, which is deemed crucial to the enhancement of the solid liquid separation in cleaning water practice.
Yet the main activity in Kiev today seems to be putting up summer terraces outside cafés, not tents for demonstrators.
Mr Welch's main activity in his part-time role at CDR is to conduct in-depth quarterly reviews of all the firms in the CDR portfolio.
His main activity in recent years seems to have been advocating the idea of a constitutional amendment to allow for national ballot initiatives, which is an interesting idea, but not one he had much to say about when he was still being included in the debates.
When Uganda revised its question about labour force participation in two contiguous surveys in 1992-93 – recording the main activity in one case, while expanding questions to cover secondary activities in the other – the percentage of working-age Ugandans in the labour force increased from 78%to87%78%to87%
Cucumber production then became the area's main activity, in part because it is also one of the Spanish vegetables that has not faced tough competition from cheaper producers like Morocco.
"The focus will be tech startups that harness large emerging market opportunities with their main activity in Africa," Partech's Tidjane Deme told TechCrunch.
As agriculture is the main activity in this part of Nalgonda district, India, the demand for groundwater resource is high.
