In this experiment, we will use an indicator to observe the reaction between acids and bases.

The use of this machine is simple.

This compound is a strong base.

He was observing the behavior of birds.

He was observing the behavior of the birds.

This computer can be used by anyone.

This chemical reaction is very dangerous.

This chemical reacts when heat is added.

The sourness of this lemon is very strong.

We conducted a new experiment in science class.