pertinacity
noun /ˌpɜːtɪˈnæsəti/
/ˌpɜːrtnˈæsəti/
[uncountable] (formal)- the quality of being determined to achieve a particular aim despite difficulties or opposition
坚定不移的；坚决的；义无反顾的 - With his usual pertinacity, he pursued this new line of enquiry.
他一如既往地固执己见，继续进行这一新的调查。
- With his usual pertinacity, he pursued this new line of enquiry.