What is this solid made of?

There are sediments at the bottom of this lake that have accumulated over centuries.

His art style is unique, it's neither fish nor fowl.

We report the progress of the project based on the principle of reporting, contacting, and consulting.

In this forest, various organisms live by building a relationship of mutualism.

In ancient Japan, the Housou clan played an important role.

Ainoya-san is my best friend.

The phrase 'the good and bad deed cancel out' perfectly describes his past actions.

He is looking for a new job at the public employment security office.

He always buys cheap things, so in the end, it becomes 'penny wise and pound foolish'.