[jiān chí bù xiè]
adhere to sth. unremittingly; hold on consistently and persistently; unremitting
make unremitting efforts
作堅持不懈的努力
Persevere and you'll succeed.
只要你堅持不懈， 你自會成功。
The broad working masses were undaunted, and persisted in their struggle with the result that the Qing government did not dare to conclude a new treaty with the imperialists.
廣大勞動人民堅持不懈地進行斗爭， 終于迫使清政府不敢公然和帝國主義續訂新約。