18. In many parts of America, a surprising number of folksy, regional, and rural expressions have developed _______ the years and, even today, are heard and used by many American speakers of English. A large number of these _______ sayings also live in the memories of today’s citified adults who can remember hearing their grandparents use these sayings frequently. (A) in; unbelievable (B) over; unfastened (C) during; figurative (D) through; colorful