31 at random; at will

● at random指“随意”摆放东西、做事情，无目的、无秩序，多位于句末。如：I was only guessing at random.（我不过随便猜猜罢了。）He took a book at random off the shelf and started to look it through.（他信手从书架上取了本书浏览起来。）She did her exercise at random.（她漫不经心地做练习。）The teacher picked several students at random from the class and asked them to help him with the experiment.（老师随意挑几个学生，请他们帮他做实验。）

● at will主要指意志方面或行为方面的“随意”，多位于句末。如：You are free to come and go at will.（你可来去自由。）I can ride my bicycle faster or slower at will.（我能任意操纵我的自行车，快慢自如。）You may read aloud at will.（你可以任意朗读。）As long as the work gets done, no one minds when I do it—I can come and go at will.（只要能完成工作，谁也不来管我什么时候工作—我可以来去自由。）