不知凡几

bù zhī fán jǐ

ㄅㄨˋ ㄓ ㄈㄢˊ ㄐ一ˇ

不知凡幾

不知凡几是中性词。

清 顾炎武《钱粮论上》：“其逃亡或自尽者，又不知凡几也。”

比比皆是

寥寥无几

can't tell how many there are (there being countless similar cases)