At its heart is a "solar tracker" made of old bicycle sprockets, springs and rocks.

最核心的部分是一个“太阳能追踪器”，由废旧的自行车链轮齿、弹簧和石头组成的。

youdao

At its heart is a "solar tracker" made of old bicycle sprockets, springs and rocks.

最核心的部分是一个“太阳能追踪器”，由废旧的自行车链轮齿、弹簧和石头组成的。

youdao