1)Whenever work is being done,energy is converted from one form into another.
问题描述：
1)Whenever work is being done,energy is converted from one form into another.
2)Whenever work is being done,energy is being converted from one form into another.
为什么第一句话正确?
答
第二句是被动的进行时,而句子是描述的一般状况,从whenever就可以看出,所以要用第一句,就如一楼说的,这里不是要说明过程,而是描述一个事实.