by doing sth.可以省略by吗?Many vaccines are made using genetic modification.这里made后跟了一个using,事实上,using前是否应该有个by呢?这个是一个什么语法现象呢?好像还没解释到这里为什么made后可以加doing

do sth by oneself ,by可以省略吗 do sth by oneself ,by可以省略吗?若不能省略和do sth oneself 有何区别? by to do sth=by doing sth吗 解释do sth by doing by doing sth.可以省略by吗?Many vaccines are made using genetic modification.这里made后跟了一个using,事实上,using前是否应该有个by呢?这个是一个什么语法现象呢?好像还没解释到这里为什么made后可以加doing stop sb from doing sth 中from可以省略吗 succeed in doing sth 中 in可以省略吗? Help sb in doing sth中的in可以省略吗?. succeed in doing sth 的in可以省略吗?阿 by ourselves做状语时可以省略by 如：we can do it well by ourselves可以省略by吗? 有没有through doing sth.的用法的和by doing sth.有区别吗 by doing sth造句10句 “by+doing sth”表示方式的用法 what do you mean by doing sth? 是不是有honour sb with sth 或者 by doing sth 用 do sth by doing sth和do sth by mistake 造句 prefer doing sth to sth动词一样是否可以省略动词prefer doing sth to doing sth如果两个doing一样是否可以省略第二个doing 用英语说:以..谋生BY可以省略吗