Everyone will go through life's stages of ups and downs, ________ selfrespect plays a key role in the maturity(成熟) of a person.
We should take effective measures to the infectious disease.
Since Tom downloaded a virus into his computer, he cannot open the file now.
If you are from doing something, you are officially prevented from doing it.
The school offers many _____ activities for the local students.
It is ______ that the noise around us is a(n) _______ to our health and well being.