What's the difference between simple and compound interest?

Which pronoun has an unclear antecedent in the following sentences? the sixth-grade students liked volunteering their time to read to the elderly people in the hospital. it made them happy. a. their b. it c. them d. no unclear antecedents

The following force measurements were taken during actual testing of the lever pictured. what is the ama of this lever?

1.how is germany's economic system similar to that of the united kingdom a.both are free-market economic b.both are command economic c.both are mixed economic d.both are traditional economic