One should stick to ______one has begun.
Our bodies are strengthened by taking exercise. ________,our minds are developed by learning.
Smoking is one of the ________causes of cancer,killing millions of people each year.
In a sports team each player has a clear role,and there are few occasions ________members are confused or uncertain about their roles.
—I’m green at everything. —Don’t worry. ________you get older,you will get more experience.
As a film star she was a success,but as a wife she was ________failure,so their marriage ended in ________failure.