If we one of the other uploading approaches, the process would have taken longer than one hour.
A. used
B. had used
C. should use
D. would use
网友回答
A. used
(答案→)B. had used
C. should use
D. would use
解析：句意：如果我们使用其他上传方法，那么这个过程要超过一个小时。分析句子结构和时态可知，题干是表示与过去事实相反的虚拟语气，故从句谓语动词用had done形式。