What is this solid made of?

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

The Cultural Revolution is a part of China's history.

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

It is important for us to respect cultural diversity and understand each other's differences.

The study of organic compounds is an important field in chemistry.

This inorganic compound plays an important role in chemical reactions.

Sandwich compounds are being studied in a branch of chemistry.

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

Acidic oxides react with water to produce acids.