The only useful knowledge is that which teaches us how to seek what is good and avoid what is evil.

She thanked him for his helpful advice.

He has given us useful knowledge.

He has given us useful knowledge.

He has given us useful knowledge.

The horse is a useful animal.

Sunshine is beneficial to plants.

Perhaps the book will prove useful.

The new discovery proved useful to science.

I got a useful piece of information out of him.

It was of great benefit to me.

Ultimately, space flight will be beneficial to all mankind.

Rocks and minerals are useful for us in many ways.

Worms are sometimes beneficial to soil.

That's not a useful piece of information.

Service economy is a useful labor that does not produce a tangible commodity.

He will give you some good advice on this matter.

This book is of great use.

This book is at once interesting and instructive.

Edison invented many useful things.