单选题We all know that doi

问题补充：

单选题Weallknowthatdoingmorningexercises______.A.is good for our healthyB.are good for our healthyC.are good for our healthD.is good for our health

答案：

D解析for后面健康应为名词，抽象事物一般用单数形式，所以选D。