以下哪个是拖拽元素事件( )
A. ondragenter
B. ondragleave
C. ondragend
D. ondrop
以下哪个是目标元素事件()
A. ondragstart
B. ondrag
C. ondragend
D. ondragenter
( )情况下会触发ondragenter事件
A. 当源对象进入目标元素时触发
B. 当源对象悬停在目标元素上方时触发
C. 当源对象离开目标元素时触发
D. 当源对象在目标元素上方释放鼠标时触发
People's learning activities are possible because they ________
A. enjoy being rewarded for doing the right thing
B. know what is vital to the progress of society.
C. believe that emotions are fundamental for them to stay alive.
D. benefit from providing help and support to one another.