1.be used for 用來...
例句:Either direct or alternating current may be used for driving electric trains.
直流電和交流電都可用來驅動電氣火車 。
2.make the point 指出,說明
例句:To make the point clearer, consider another example.
為了更為清楚地說明這一點,讓我們再來考慮一個例子 。
3.approached about 與...接觸
例句:Have you approached the manager about taking a day off next week ?
你是否同經理談過下周請一天假的事?