is diligent
あなたの妹は友達の中で一番勤勉です。
Your younger sister is the most diligent among her friends.
彼は誰にも負けないほど勤勉です。
He is as diligent as anyone.
彼は学生並みに言えば勤勉です。
He is diligent by student standards.
彼は勤勉です。
He is hardworking.
彼は学生並みから言えば勤勉です。
By student standards, he is diligent.