Ferrofluids
(ferrofluid 的復數) 鐵磁流體
??? 情景例句
A dog!
一只狗！
Excuse me I couldn't write you sooner.
對不起我不能盡快給你寫信。
He had been obliged to join the army during the Second World War.
年齡比他兩個弟弟大很多，第二次世界大戰期間被迫參軍。