This is a problem not infrequently encountered by postdocs.

这是一个博士后学生经常遇到的问题。

《柯林斯英汉双解大词典》

I visit them not infrequently.

我经常拜访他们。

youdao

Not infrequently does the septuagenarian go abroad.

那个年逾古稀的老翁经常出国。

youdao

If there was a power outage or an internet problem at my house, which not infrequently happens due to storms, everyone is shut down, including me.

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The American press not only had a field day reporting the details but not infrequently lectured their pusillanimous British colleagues about American ideas of press freedom.

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Before departing the presidential race, former Minnesota Governor Tim Pawlenty would not infrequently criticize Rep. Michelle Bachmann for lacking a record of legislative success in Congress.

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