“这是一个变距螺旋桨，就像在自行车上安齿轮一样，”兰德说。

"It's a variable-pitch propeller, which is like having gears on a bike," Land says.

youdao

“这是一个变距螺旋桨，就像在自行车上安齿轮一样，”兰德说。

"It's a variable-pitch propeller, which is like having gears on a bike," Land says.

youdao