根据句意和所给的中文提示，写出句子中的单词。

Could you please tell us about the four great____ (发明) of China?21世纪教育网

He’s already____ (喂养) his pet dog.

My grandfather is interested in____ (收集) old coins.

The dentist suggests that we should brush____ (牙齿) three times a day.

After the sudden earthquake, most of us were____ (醒着) all the night.