I heard that footprints of an abominable snowman were found in the Himalayan mountains.
- I heard that footprints of an abominable snowman have been discovered in the Himalayas.
Tom found out that life on the road wasn't as easy as he thought it would be.
- Tom discovered that life on the road wasn't as easy as he thought it would be.
... Europeans discovered sugar in the Middle East during the Crusades, ...
... who made the series work. In particular, a physicist. He was the one who discovered ...