mountain为什么加sshe's camping in the mountains为什么山要加s?是说她在很多山上camping?还有,为什么用介词in 不用on?全部问题都要回答!

mountain为什么加sshe's camping in the mountains为什么山要加s?是说她在很多山上camping?还有,为什么用介词in 不用on?全部问题都要回答! a mountain of mail 中mail 为什么不加s It's snowing in the mountains中mountain为什么要加s in the mountain(能加s吗?) She with her mother want to go shopping?中的want要不要加sShe wants to go shopping with her mother.这是肯定要加S的. she now works as a math teacher at a high school work为什么+sshe now works as a math teacher at a high school work为什么+s It's two day's walk form one side of the snow mountain to the other side.中的day’s为什么要加‘号s she‘s a good student and is always the best in the class in her studies中的studies 为甚么要复数啊?是三单的缘故吗?可是学习是动词吗?那“always“为什么加sshe often helps me with my studies.中的学习也是三单吗?（ there will be thunder shower in the()是mountain area 还是area of mountain,还有要不要加s? 是go to the mountain还是go to the mountains?加不加s,想这类的都加不加s?如是go to the moviesgo to the movies加啊！为什么有的加有的不加 The local farmer's question is ____ They can findsuch a plant in mountain.A.where B,if.c.how.D,what.为什么不能使where 在英语单个名词后面能加s吗?是这些单词：banana　　　　　flower　　　　　mountain Trees are planted in most of the mountain v__ village加s 为什吗 did you like climbing the mountain的moutain要加s吗 英文初级语法let,s go to the mountains. 让我们去爬山吧. 问题：那个“山”的英文mountain为什么要加s呢?这句话没感觉到要用复数形式吧! like为什么加s? degree为什么加S shoe为什么加s