The phrase "are often sufficient" is correct and usable in written English.
It can be used to indicate that something is usually enough or adequate in a particular context.
Example: "In many cases, basic safety measures are often sufficient to prevent accidents."
Alternatives: "are usually adequate" or "tend to be enough".
With optimal receiver depths, depending on propagation range, only a few, sometimes only two, hydrophones are often sufficient for low BERs, even with intermediate mode numbers.
While three or four replicates are often sufficient for compensation of variability, the pilot study illustrated in this chapter showed that statistically significant expression differences could be detected for 90% of the spots matched if six replicate experiments were done.
We show that while explicit methods for coupling the incompressible Navier Stokes equations and Newton's equations of motion are often sufficient to solve for the motion of cylindrical particles with low density ratios, for more complex particles – such as a body with a protrusion – they become unstable.
AP and lateral x-rays are often sufficient for diagnosis [10, 26].
One or two indicators are often sufficient, but three indicators may occasionally be helpful.
Although all three entities cause penile pain and swelling, history and physical examination are often sufficient to make this distinction.
To preserve analog information resources, it is often sufficient to house them in a benign environment.
But one male holly in the neighborhood is often sufficient to pollinate the females, which have the berries.
"There is some anecdotal evidence that the threat of an Asbo is often sufficient," says a spokeswoman.
Though the result may not be perfectly precise, he believes, intuitive mathematical reasoning is often sufficient for our needs.
A business-friendly government and cheap workers were often sufficient to get started; foreign firms provided technology and management.
