The phrase "across four regions" is correct and usable in written English.
It can be used when referring to something that spans or is distributed over four distinct geographical or conceptual areas.
Example: "The study was conducted across four regions to gather diverse data on climate change impacts."
Alternatives: "in four areas" or "throughout four regions".
We examined DNA methylation across four regions of the placenta to evaluate methylation levels of stress-related genes within a healthy placenta, and to evaluate whether methylation patterns vary by sampling location.
They are distributed across four regions according to the classification of the Development Commission of Rangeland (1980): the western, central and eastern regions, located above the 50-mm isohyet, and the southern region, located below the 50-mm isohyet (Figure 1). Figure 1 Distribution of Libyan rangeland in relation to terrain and rainfall.
Entering Sweet Sixteen round with four strong contenders spread across four regions, there was talk of the conference matching or surpassing the 1985 Big East Conference performance with three final four entrants.
19 The 500 participants were older Thai adults living in communities across four regions of Thailand.
Ten provinces and 20 districts were stratified-cluster randomly selected across four regions in Thailand and Bangkok.
Ten provinces and 20 districts were selected across four regions of Thailand (i.e., Northern, Northeastern, Central, Southern) and Bangkok using a stratified-cluster random sampling.
"ABI Research tracked Chromebooks across six regions and found the ASP to be US$338," said research analyst Stephanie Van Vactor.
There are eight RSCs across eight regions in England; rather than intervening directly, RSCs commission teaching schools and other beacons of excellence in education to improve underperforming schools.
We know from working in schools across seven regions in England that the quality of teaching and leadership in a school can enable children to overcome social disadvantage".
The project has recruited only the first few of a hundred or so workers whom we are sending out to hospitals across six regions of Uttar Pradesh in a trial that will involve almost two hundred thousand births over two years.
Over four days and across three regions in Slovakia, his appearances provided the most vivid examples yet of the heavy toll that Parkinson's disease has taken on him.
