请问:our mind and effort 中的mind 和effort 要不要加s

请问:our mind and effort 中的mind 和effort 要不要加s spare no effort effort要加s吗 effort什么时候加s 初三英语疑问关于effort加和不加s make efforts to do sth.为什么effort要加s? change one's mind 和 make up one's mind 那个mind能加S那个不能加? making no effort 和 make every effort let's make a effort to protect our environment 请问We should make every effort to protect our environment. There is a thing in my mind is no matter what a small effort make efforts to do sth.为什么effort要加s,它是可数名词吗? It`s worth your time and effort.怎么翻译