【题目】Laughter produces short-term changes in the function of the heart and blood circulation,_________heart rate and oxygen consumption.
A. increasing B. to increase C. having increased D. being increased
在线课程【答案】A
【解析】考查非谓语动词。句意：笑可以使心脏运转和血液循环产生短期改变，增加心率和耗氧量。根据与逻辑主语Laughter是主动关系，故用现在分词作状语，起补充说明的作用。故选A。