heart與lung都是可數名詞
例句如下,請仔細體會和理解吧
1、
Every so often the horse's heart and lungs are checked.
不時檢查那匹馬的心臟和肺。
2、
The lungs are in fact constructed of thousands of tiny tubes.
肺實際上由上千條細微的氣管構成。