private first class

private-first-class的词性：
n.（名词）

1. A noncommissioned rank in the U.S. Army that is above private and below corporal or in the U.S. Marine Corps that is above private and below lance corporal.
一等兵：美国陆军的非士官军衔，高于二等兵，低于下士或在美国海军陆战队中高于二等兵，低于海军下士

2. One who holds this rank.
一等兵：持有一等兵军衔的人