a little earlier, you could have caught the last bus.
A. If you would arrive
B. If you arrived
C. Should you arrive
D. Had you arrived
网友回答
A. If you would arrive
B. If you arrived
C. Should you arrive
(答案→)D. Had you arrived
解析：句意：如果你早一些到达，你就可能赶上最后一班车了。从you could have caught the last bus.可知前面是和过去相反的虚拟条件句，If you had arrived a little earlier,这时可以省略if，提前had，所以选D。