helical-fin section

例句：

1. 1. The aircraft'sengine is located in the helical-fin section.
   飞机的发动机位于螺旋桨部分。
2. 2. The engineer carefully dismantled the helical-fin sectionto inspect the damage.
   工程师小心翼翼地拆解螺旋桨部分以检查损坏情况。
3. 3. The helical-fin section plays a crucial rolein propulsion efficiency.
   螺旋桨部分在推进效率中起着至关重要的作用。