Changes in the social system inevitably occur with time.

We should think deeply about the reform of the social security system.

This system is necessary to maintain social fairness.

He likes to think deeply.

We believe that we need to reform the education system.

We believe that a reform of the education system is necessary.

This product comes with a one-year guarantee.

We guarantee your safety.

His eyes are a deep blue.

We should take responsibility as part of society.