at discretion的用法和樣例：
例句
- He has put his car at my disposal.
他已把車子讓給我隨意使用。 - I allow students to come and go at discretion.
我允許學生們隨意的來來去去。 - They come and go and wander at their will.
他們任意地來去游逛。 - I was the first to arrive at the inn and got the pick of rooms.
我第一個到達旅館，可以任意選擇房間。 - I didn't buy it for I knew I was entitled as its author to at least ten complimentary copies.
但我沒有買它，因為我知道，至少可以無條件地得到十本的。
