It seems oil _______ from this pipe for some time.We’ll have to take the machine apart to put it right.a、had leaked b、 is leaking c、 leaked d、 has been leaking为什么选D?请翻译整句

问题描述:

It seems oil _______ from this pipe for some time.We’ll have to take the machine apart to put it right.
a、had leaked
b、 is leaking
c、 leaked
d、 has been leaking
为什么选D?请翻译整句

看上去油已经从这个管道里漏了一段时间了.我们得把机器拆开来把它的位置摆正.
持续的一段动作,并且现在还在继续且对现在有影响,所以用完成进行式.