New medicines and instruments ______ every day to extend life.

 — Why do you do volunteer work in the North-West?— I_______ to improve the lives of the children there through my efforts. 

—Why don't we choose that road to save time?—The bridge to it ________.

Though the medicine for my disease______, I should often______ at home or in the open air.

Although the causes of cancer ____we do not yet have any practical way to prevent it.