Please line up one by one.

Which book is older, this one or that one?

Please come into the room one by one .

As one grows old, one becomes a light sleeper.

When one would be filial, one's parents are gone.

I prefer one-to-one conversations over group discussions.

One of my favorite hobbies is reading, another one is painting.

One is more prone to make mistakes when one is tired.

The older ones do not always know more than the younger ones.

One's success in life has little to do with one's inborn gift.