In the experiment we kept a watchful eye （ ） the developments and recorded every detail.

—Professor Wang, must I hand in the paper this week? —No,（ ） . You can hand it in next week.

She is very （ ） to his ugly appearance.

Air pollution is obviously one of the major _____ of city life.

Mr. Jones, _____ life was once very hard, is now very successful in his business.

She （ ） tell white lies to make people feel better, to smooth things over.

I love thinking of new designs. It keeps my mind clear and active and fills my retired life with （ ）.

The government cannot operate effectively （ ） it is free from such interference.

The doctor said that mental （ ） is the major cause of his sleeping problem.

Space vehicles were launched into outer space_____search of another living planet.

John Smith, a diligent student, never refuses to （ ） more responsibilities that are assigned to him.

（ ） the past year as an exchange student in Hong Kong, Linda appears more mature than those of her age.