The systems' self-repair and self-maintenance functions have encountered more insurmountable obstacles.

But every hour they encountered more and more insurmountable obstacles.

At 95, his body had become frail and weary, making the fight against cancer more insurmountable.

My men were in absolute despair, for the farther we went the more insurmountable became the obstacles which confronted us.

But still, the difficulties in his path seemed to be rendered more insurmountable than ever by the arrival of James.

The obstacle which he carried in his face was frightful; but the obstacle which he carried in his ideas was still more insurmountable.

For he was a man who spared no one; and then a new obstacle would rise between them, more insurmountable still than the others.