“膝部”造句

呼气，膝部放松向胸部靠拢。
Breathe out and ease your knees in toward your chest.

他的一条腿不得不从膝部以上截断。
He had to have one leg amputated above the knee.

送信人弯下腰来，挠着膝部被绑腿磨红的地方。
The messenger bent and scratched at his knee where the strapping chafed.