Because the old people about thirty percent of the population we should care more about

问题补充：

Because the old people about thirty percent of the population, we should care more about them.

A. look up

B. fix up

C. make up

D. end up

答案：

A. look up

B. fix up

(答案→)C. make up

D. end up

解析：look up“查阅”，fix up“修理”，make up“组成，占到”。end up“结束”根据题意，应该选make up。本句的意思是“因为老人占到人口的百分之三十，所以我们应该更关心他们。”所以本题选C。