Astronauts must get a lot of exercise.为什么这里的exercise不能加s?

get a lot of exercise翻译 do a lot of grammer exersices中为什么exercise要加s do a lot of exercise 还是do lots of exercise 为什么 1.she gets some exercise中这里的exercise要不要加s? 是a lot of exercises ,还是lots of exercise?为什么?lots of和a lot of I take a lot of exercise and am very fit 中的am为什么是对的? 为什么 favorite exercise中exercise不用加s It's good exercise.为什么good前不用加a? He wants to get a lot of exercise改为一般疑问句 astronauts must exercise for ( ) every day in space so they What a lot of trouble he is causing 这里的 trouble 为什么不是复数 加 S 为什么是a lot of exercise而不是a lots of exercises?