Sororate
n. 先后娶姐妹數人為妻的婚姻\\n[法] 與妻的姊妹結婚的風俗
??? 情景例句
and from the University of Michigan in 1956.
一九五六年從Michigan大學畢業。
Our first bill came yesterday, and we have some questions.
我們昨天收到的第一張帳單，有一些問題。
Once the oxygen content of the air had risen to 25% it was ready to burn.
一旦氧氣在空氣中的含量達到25%，它就要燃燒。