"Because if we wait for a prolonged period, there may not be anything left to study."

I don't think it's something we have to do for a prolonged period of time.

This can bring a prolonged period of change into the person's life.

I don't think a prolonged period of uncertainty is a good thing.

They open in succession over a prolonged period and last well.

If you must sit for prolonged periods, take a break every hour.

These changes cannot happen over a prolonged period without producing a new species.

It's the first time so many have gathered for such a prolonged period.

He died in 2011 at the age of 72, after a prolonged period with prostate cancer.

"We wanted to know what the cardiac activity was over a prolonged period."