We have to ____ ourselves when we are away from home.

Mr. White had no money for the taxi, so he had to ______ home.

Most Asian women try to be shaded from the sun while touring in Europe in summer, fearing that the strong sunshine may ______ the aging process of their skin.

If _____ carefully, the experiment will be successful.

Tina always goes to school_____breakfast. It’s bad for her health.[ ]