Seroconversion
n. [生][醫]血清轉化
??? 情景例句
They have an opening.
他們有一個空房間。
When two ride on one horse, one must sit behind.
兩人共騎一匹馬，總有一個背后跨。
We believe that the quality is the soul of an enterprise.
我們認為質量是一個企業的靈魂。