为什么要加ofthese studies revealed that these vibrations were of two types,compression or P waves and Shear or S waves,这里面"were of two types",为什么要加个of

为什么要加ofthese studies revealed that these vibrations were of two types,compression or P waves and Shear or S waves,这里面were of two types,为什么要加个of he is good at studies.studies.为什么加s. She studies in a school studies 是She studies in a school studies 是 研究 的意思 意思应为 她在学校研究 为什么书上是 她在学校学习 为什么要加 he studies hard at school when he was young,which leads to his success in his later life.为什么用studies而不是studied 为什么这里用leads 就是为什么要加s? Two years ago ,Sally was in a high school.Today,she studies in collage在这个句子里a high为什么要加a不加可不可以 Diara,together with her firends studieschinese in China?为什么在studies前加have? how is Buzz getting on with his studies中study为什么加es some students are indulged in these activities,totally neglecting their studies.后面为什么加ing 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?（ 动词各种时态的详细变化1、单三：copy单三要去y加ies -copies,而play-played,请告诉我为什么.2、复数形式：study复数要去y加ies-studies,而boy-boys,请告诉我为什么.3、过去式：copy过去式要去y加ied-copied My sister studies hard .为什么不用hardly Studies show that those who drink and smoke a lot are more likely to suffer a heart attack.show为什么后面不加S? Diana,together with her firends studies chinese in China.为什么在studies前不加have? then she studies at school and goes home in the aftermoon 是不是用studies 为什么 One of my friends studies art 为什么这里的study是studies? 帮忙解释几个英语单词的词性和意思Concentrate more on clothes than studies 中的studies 为什么要去Y变IESgreat well good这但个单词的词性分别是什么,意思是? Diana,together with her firends studies chinese in China.如题 谢谢了Diana,together with her firends studies chinese in China.为什么studies?为什么用三单呢 还有he get 2000 yuan from the __________（sale） of the oil painting.要加s吗?she is studying at school 还是 studies at school