为什么by后面doing through后面接名词或代词

为什么by后面doing through后面接名词或代词 through doing something 是否等于by doing something 有没有through doing sth.的用法的和by doing sth.有区别吗 by 后面应该加什么?为什么有时加的是名词,如：by bus,有时是by + doing?有什么区别?怎么区分呢?请 Doing work means moving a body through a distance by force Doing work means mobbing a body through a distance by a force什么意思啊? still 后面为什么要加doing by doing a river goes through the center of the town,这个thecenter为什么在through后面呢? through doing sth rather than through doing sth by through this way, 为什么写信后面落笔by是什么意思? the security deposit can be paid by paid by check which is held and retuened to you after doing a walk-through following your party,.4213 devote (time)to后面跟do还是doing?为什么? make a contribution为什么后面加to doing be afraid of 后面为什么加to do ,而不是doing? 为什么be addicted to 后面一定要加doing about 是什么词性?为什么后面要加doing