diligent
adjective uk/ˈdɪl.ɪ.dʒənt/ us/ˈdɪl.ə.dʒənt/
approving认真刻苦的，勤奋的，勤劳的
careful and using a lot of effort
a diligent student 用功的学生
Leo is very diligent in/about his work. 利奥工作非常勤奋。
Their lawyer was extremely diligent in preparing their case. 律师为他们这个案子做了认真扎实的准备。
细致的，潜心的
done in a careful and detailed way
The discovery was made after years of diligent research. 这一发现是数年潜心研究的成果。