The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Scientists have been finding evidence of life inside meteorites for well over 100 years — that, or the building blocks of life. The claims of life have proved false every time. It always turns out to be a wishful interpretation of chemicals, minerals and tiny structures inside the meteorite that could be the fossilized long-dead bacteria — but almost certainly aren't.
Scientists （） to find valid evidence of life inside meteorites.