上传
The student looked at his teacher with upcast eyes. 学生眼睛朝上看着他的老师。
Don't upcast or chuck the scaffolding materials and don't leave behind the material on scaffolding. 不可以上抛及下扔脚手架材料，不许遗留脚手架材料在架子上；
"Go down oneself from cliff upcast, fall on the ground before, I learned to fly. “把自己从悬崖上抛下去，摔到地上前，我学会了飞翔。”
It results from to poverty person a true understanding course of ability, abandon old idea from thought upcast and establish new idea. 它源于对贫困者的能力的一个真诚的熟悉过程，从思想上抛弃旧观念而树立新观念。
All you need to do is upcast from the derived class and never look back to see what exact type of object you're dealing with.Everything is handled through polymorphism. 你只需要将对象上传转化为基类对象不需要知道额外的信息，而这些都是通过多态实现的。
