你可以看到飞机的螺旋桨。

You can see the airplane's ___propeller.

飞机起飞时，螺旋桨高速旋转的声音很大。

The ___propeller makes a loud noise when spinning fast during takeoff.

他的热情成为团队前进的推动力。

His enthusiasm served as the ___propeller for the team's progress.