She sits on a metal base with wheels that let her move around, turn in tight spaces and climb over small objects.

她坐在安有轮子的金属底座上，能在四周活动，在狭小空间转弯，并翻越小物品。

Difficult words: acceleration (how quickly can something move faster), optimize (to make something as good or effective as possible), chassis (the metal base of a car).

困难的词：加速（某物移动得更快的速度）、优化（使某物尽可能好或有效）、底盘（汽车的金属底座）。