Sentence examples for proved so hard from inspiring English sources

These findings may help explain why it has proved so hard to isolate the genetic roots of disease.

Leon Lederman, a leading researcher in the field, once dubbed it the "goddamn" particle, because it has proved so hard to isolate.

Why, then, has the rift that has opened in the United Nations Security Council over the disarming of Iraq proved so hard to heal?

This self-effacing composer proved so hard to track down that Mr. Runge thought "he must be a phantom," he said.

But the risk, though very small, that a man facing execution could win a new trial raises the question why this rule has proved so hard to follow.

All the big countries' voting weights have increased at the expense of small countries.This change proved so hard for the small countries to swallow that it brought them to the brink of walking out.

So why is the Ebola epidemic proving so hard to contain?

If it is, it's no wonder it's proving so hard to eradicate the stigma of mental health problems.

Life-jacket pouches have proven so hard to open that some passengers have had to use their teeth.

And what made sense when Alistair Darling introduced it in 2009, with the economy set for recovery, is less prudent now, with growth proving so hard to find.

He focused more and more on favorite issues -- notably global warming -- that had proven so hard to translate into a presidential campaign agenda in 1988.