doubtlessly correct
doubtlessly certain
doubtlessly true
A: Do you think he can finish the project on time?
A：你认为他能按时完成这个项目吗？
B: Yes, he is doubtlessly very hardworking.
B：是的，他毫无疑问工作非常努力。
1) 毫无疑问地
2) 肯定地
3) 确定地
1. 毫无疑问地，确定地
adverb
1. In a manner that is certain and without any doubt.
Synonym: certainly, undoubtedly