单选题 The floods did not start to ______ until two days after the rain had stopped.

【正确答案】 B

【答案解析】[解析] retire指人、军队等“退职，退位，退休，退役”。retreat指军队“撤退”，回避。recede可以指潮水退去。sink意为“下沉”。句意为：直到雨停了两天以后，洪水才开始退下去。所以，本题选B。