She tends to be mentally unstable.

In physics, the gyroscopic motion is an important element in controlling the rotation of an object.

In the old days, people used to consider milk as an important source of nutrition.

The Earth is our home.

Tom was proud of his knowledge and wisdom.

My father is a doctor.

Daichi is my best friend.

He studies hard every day.

When a baby starts weaning, you begin to give them solid food little by little.

The baby has started to wean.