Raw materials are essential for the production of many products.

The foundation stone was laid today to mark the beginning of the construction.

The front cover of the book is very attractive.

It is an essential product.

I got this information straight from the horse's mouth.

At first sight, he seemed very friendly.

The First World War lasted for four years.

She dove headfirst into the pool.

We are going to lay the first stone of this project tomorrow.

The courts of first instance are responsible for handling civil and criminal cases at first instance.