He started studying the day before the exam, which was exactly a case of failing to make a timed preparation.

He was my student, but now he has become so proficient that it can be said 'the student has surpassed his teacher.'

Kazumi is my best friend.

I have been to Suishiei.

Water Margin is one of the four great literatures of China.

I buy water at the water store every day.

This compound contains a sulfhydryl group.

The aquifer in this area provides a very abundant water source.

My favorite classic novel is Water Margin.

Groundwater pollution has become a serious environmental problem.