He came to America as an immigrant when he was young.

In this area, beneficial animals play an important role in maintaining the balance of nature.

He entered the forest with a shotgun.

The specific gravity of this substance is higher than water.

This factory uses fuel oil as its main fuel.

I am planning to go to Chongqing next week.

He was obedient to what his parents said.

He cooked using a gas stove.

This square matrix has the same number of rows and columns.