We don't (be not sure if something is true)the great achievements China has made in the past 40 years.
To be safe,students should (避免) going out alone at night.
At the age of (四十), the writer finished his fifth novel.
You should (道歉) to her for your mistake.
Liu Yang is the first Chinese woman (宇航员) to enter the space.
It's our duty to protect the (环境).