qua

1. Agreement by the management is a sine qua non of all employment contract.
   管理部门的同意就是所有雇用合同的必要条件。
2. Patience is a sine qua non for a good teacher.
   做个优秀教师必不可少的条件是要有耐心。

qua

prep.（介词）
In the capacity or character of; as:
以…的资格，或以…身份；作为：
例句：
The President qua head of the party mediated the dispute.
总统以党的领袖身份出面调解这场争端

来源：
Latin qu3 [feminine ablative sing. of] quo [who] * see k wo-
拉丁语 qu3 [] quo的阴性夺格单数 [谁] *参见 k wo-