She would have finished the last page of her play, but she ______ to stop to feed her crying baby.
【正确答案】 C
【答案解析】考查时态。她停止写剧本去给小孩喂奶是真的，而且已经发生，所以用过去时。has to的过去时是had to，没有过去完成时had had to这种说法，故选C。