------ we think it is a miracle that they were able to do so

问题描述:

------ we think it is a miracle that they were able to do so
A to this day B up till now 选哪个?新概念上面的迷糊了

答案是 to this day
To this day is the most colloquial and fits the use of still in the
original sentence.
Up till now suggests that we have probably just decided it was not a
miracle (and would be followed by thought), Up till now
may suggest that the situation has just or is about to change.