25. A lot of coal miners died on the job last year, ________ the government to shut nearly 500 small mines in Shanxi Province alone. 
A. forcing                    B. to force                C. forced               D. having forced
26. ---- Can you explain ________ it came about that you were an hour late?
   ---- Sorry, sir. I overslept.
   A. where                     B. why         C. how                      D. whether