Daichi is my best friend.

My father is a doctor.

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

He studies hard every day.

My younger brother got infected with pinworms.

My younger sister got infected with pinworms.

This 蟯蟲 is a very rare type of parasite.

When summer comes, we take measures to repel insects inside the house.

It's a natural phenomenon for newborns to secrete witch's milk.

She is the owner of a 'kijitsu'.