The phrase "are extremely effective at" is correct and usable in written English.
You can use it to describe the high level of effectiveness of a person, method, or tool in achieving a specific goal or task.
Example: "The new marketing strategies are extremely effective at increasing customer engagement and sales."
Alternatives: "are highly successful in" or "are very efficient at".
One thing everyone can agree on is that statins are extremely effective at lowering cholesterol.
The sounds travel long distances through the water and the sonar are extremely effective at detecting noises, especially from a ship that is not trying to hide.
The administration's position is particularly untenable when the Environmental Protection Agency's own scientists concluded -- on the same day -- that strong air quality protections are extremely effective at removing mercury from the environment.
No one is very sure, but safety experts stress that while helmets do not prevent accidents from happening, they are extremely effective at reducing the severity of head injuries when they do occur.
ARV cocktails are extremely effective at treating HIV-infected people, but the drugs have serious long-term toxicities and must be taken every day.
They are extremely effective at preserving physical properties of polymer during and after γ-sterilization, but at the expense of yellow color formation [8].
George Osborne referred to these schemes as morally repugnant so why isn't he doing anything to stop them?" An HMRC spokesperson said: "HMRC is extremely effective at shutting down tax avoidance schemes fast and effectively.
Advertising like this is extremely effective at helping smokers make the cognitive changes needed to quit.
"Testing has been shown to be extremely effective at reducing drug use in schools and businesses," the government guide said.
"[Chlorine], although militarily not a very efficient way of conducting war, is extremely effective at sowing terror.
