作狀語：
Seen from the hill,the city is beautiful.
從山頂看,這座城市非常美麗。
Confined to bed (= Because she was confined to bed),she needed to be waited on in everything.
她臥病在床,什么事都需要人伺候。（作原因狀語）
Having only book knowledge (= If you only have book knowledge),you will not be able to work well.
如果只有書本知識,你就不可能做好工作。（作條件狀語）