#看拉丁学英语#sine qua non 必要条件="without which not" 没有就不行; sine“without”+qua“which”(qui“which”的阴性单数离格)+non“not” 派生词:sine die无期限地(without day,dies“day”的离格,比如单词diurnal每日的);sinecure闲职(without care,cur“care”比如curious,secure