The ecosystem of this lake is very fragile.

In physics, the inertial frame of reference is a very important concept.

My accounting job is to keep a record of monetary transactions.

It is estimated that the project will take about two years to complete.

We need to estimate next year's sales.

The system of this company is very efficient.

He was wearing a cone-shaped hat.

The central nervous system is responsible for transmitting information and controlling the body.

Japan is receiving most favored nation treatment from the United States.

The water system of this area is very complex.