To keep ______ with the rapid changes of society, the old man keeps the habit of reading newspapers every day.
Read the passage a second time, ___________ the meaning won’t become clearer to you.
When she finished her story, none of us said anything about it, which made her feel rather ________.
E-mail, as well as phone calls, _____________ an important part in daily communication.
If we don’t take steps, some rare animals, such as the Tibetan antelopes and pandas will ____________ some day just as dinosaur.
------- How can we __________ to a changeable environment? -------- By constant study and changing our ideas.