Several young men threw bottles and waste paper on the ground ______ will after they finished eating their picnic.
问题描述：
Several young men threw bottles and waste paper on the ground ______ will after they finished eating their picnic.
A.at B.on C.by D.in
应该选哪个?能把句子解释下么,我看不懂恶,
答
几个年轻人在吃完他们的野餐后,
把瓶和废纸扔在地上.
at will
选A,这里 at will 是随意的意思,will在这里是意愿