单项选择题
That ______ the case, we have to make some changes in our plan.
单项选择题 This detective story might not be ______ interesting to keep the child awake.
单项选择题 The accident ______ downtown yesterday resulted from the driver's carelessness.
单项选择题 I regret ______ you that I can't go to Hangzhou for a visit next Sunday with you, because I've caught a bad cold.
