They had known each other for forty years.
We must all try to help each other.
We have known each other for the last ten years.
Einstein has proved that matter and energy are convertible into each other.
A husband and a wife should confide in each other.
My little brothers are always fighting with each other.
Mind and body influence each other.
Men and women are both complementary to each other like the two wheels of a vehicle.
They are at war with each other.
My husband and I try not to keep secrets from each other.
We have known each other for long.