The sentence "this is very critical" is correct and usable in written English.
You can use it when discussing a situation or decision that is very important and potentially has a significant outcome. For example, "We need to make a decision quickly about whether to proceed with the project, as this is very critical to its success."
"This period is very critical and difficult.
"This technology is very critical to help reduce loads on grids during peak power," said Scott Sklar, an author of "Consumer Guide to Solar Energy: New Ways to Lower Utility Costs, Cut Taxes and Take Control of Your Energy Needs" (Bonus Books, 2002) and a consultant who has occasionally given advice to WorldWater.
"This support is very critical in order to scale up the country's efforts on Maternal and Newborn health and child survival," said Dr, Richard Kamwi, Minister of Health and Social Services.
This issue is very critical, as the need to humanize the medical education is very evident, especially in settings such as ours where patients are the main educational "tools," since clinical skills lab was not introduced until quite recently.
"This new architecture is very critical to Intel retaining its lead," said Dean McCarron, an analyst at Mercury Research.
This farming system is very critical during times of shocks as the output production of one complements the other.
In this regard, it is very critical to choose a suitable residue in the target protein structure (for cysteine replacement) that does not significantly interfere with the enzymatic activity but still allows the attached fluorescent probe to sense drug binding at the active site.
This is because inter-coder agreement is very critical in this methodology.
This implies that it is very critical in 2-D EM FEM modeling near coastlines that appropriate numerical grids are employed that allow smooth and continuous tangential components of the electric field with respect to bathymetry.
