It is similar to a sinking fund but not mandatory.

回购基金类似于偿债基金，但不是强制性。

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Foreign firms can only sell commercial auto insurance now but not mandatory auto insurance.

外国公司现在只能销售汽车商业保险，但汽车强制险却不可以。

youdao

Experience working with an application server and relational database is beneficial but not mandatory.

有应用服务器和关系型服务器的工作经验更好，但不作硬性要求。

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Medicare's first prescription drug benefit, created late last year for 40 million people, will make it optional--but not mandatory--for seniors to order drugs through the mail.

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Most countries publish the audits, but it's not mandatory, "and the ones that you really want to see are the ones that don't publish, " Voss said.

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But they do not back mandatory quotas.

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