A N S W E R T H I S P L E A S E Read this excerpt from "The Unseen Values."

Scientific research has never been amenable to rigorous cost accounting in advance. Nor, for that matter, has exploration of any sort. But if we have learned one lesson, it is that research and exploration have a remarkable way of paying off—quite apart from the fact that they demonstrate that man is alive and insatiably curious. And we all feel richer for knowing what explorers and scientists have learned about the universe in which we live.
According to the author, how can research and exploration pay off?

They allow us to learn about the universe.
They make us feel richer.
They create jobs for explorers and scientists.
They teach us not to expect immediate results.