Don't just look on when an accident happened.
事故發生了不要僅僅旁觀。
Investors can only look on, baffled.
而投資者只能困惑地進行旁觀。
he had a worried look on her face.
她一臉擔憂的樣子。
I could tell by the look on her face that something terrible had happened.
從她的臉色我可以看出，發生了可怕的事情。
There was an amused look on the President's face.
總統面帶愉悅的神情。