The pen writes ——a,smooth b,smoothly说明理由

The pen writes ——a,smooth b,smoothly说明理由
The pen writes ——
a,smooth b,smoothly
说明理由

The pen writes ——a,smooth b,smoothly说明理由
smoothly 是修饰动词的
smooth 是修饰名词的
the pen writes smoothly
那笔书写起来很流畅
her hair is smooth
她的头发很顺滑

B副词修饰动词