primary coverts

• 初级覆羽

primary coverts的用法和样例：

例句

1. Usually there is a distinct contrast between the black primaries and brown coverts, still evident at middle distances.
   长尾水剃通常在黑色的初级飞羽与棕色的覆羽之间有著明显的对比，在中距离的时候仍是可见的。