用所给动词的适当形式填空：A：Why___(do not)John___(go)to work today?
B:Because he___(break)his arm yesterday.A :I___(be)sorry to hear that.What___(happen)?B:He (fall)___off the stairs on the way to the MTR.A:John usually___(drive) to work.Why did not he___(take)his car this morning?B:He___(hear)on the radio that there was a traffic jam so he___(take)the MTR.