Difficult words: feat (an achievement that requires great courage, strength, or skill), circuit board (a set of electrical connections fixed onto a surface), chassis (the base frame of a car).

困难的词：壮举（需要巨大勇气、力量或技巧的成就）、电路板（固定在表面上的一组电气连接）、底盘（汽车的底架）。