________ many changes have _______, we should keep pace with the changes too.
5. In our class, when the bell rang and the taacher closed his book, it was a or everyone to stand up.
4. Hiking by oneself can be fun and good for health. It may also be good forbuilding.
3. Some parents are just too protective. They want to ______ their kids from every kind of danger, real or imagined.
2. During the war there was a serious lack of food. It was not unusual that even the wealthy families had to ______bread for days.
1. Would you please __the paper for me and see if there are any obvious mistakes?