She's very hard-working and serious.

她非常勤奋和认真。

youdao

My good friend Han Meimei is a very hard-working girl.

我的好朋友韩梅梅是一个很勤奋的女孩。

youdao

He was not a very hard-working student when he was young.

他年轻时不是一个很用功的学生。

youdao

She was very hard-working and always had a huge smile on her face.

BBC: Heather Stanning win cheered on by Army colleagues

Tareq Ayoub was someone who was very hard-working, an extremely helpful colleague, and we have all had very close ties to Al-Jazeera, to our colleagues there.

CNN: Rym Brahimi: Hotel known as base for reporters

I've always been a very hard-working person, but I have been amazed at the degree to which on Saturdays and Sundays I find myself involved in professional activities.

WSJ: Managing in Asia: China Eyed as Next Educational Frontier; John A. Quelch: China Europe International Business School