Pinion rack
[化] 嚙合齒條
?? 詞語組成解析
pinion
['pinj?n]
vt. 抓住[捆住]（雙臂）;
n. <術>小齒輪;
rack
[r?k]
n. 行李架;支架;刑架;（羊、豬等帶前肋的）頸脊;
vt. 使痛苦，使焦慮;剝削，榨取;用刑拘折磨;
??? 情景例句
Of course.
當然。
It's urgent to improve the packing.
必須馬上改進包裝。
A few peopple in each group are given the task of remembering the group's family history that goes back over centuries.
每一個家族都有幾個人擔任記憶延續了幾個世紀的家史的任務。