单选题 The first year of the college life is a very complex ______ period, and the more fully the freshmen prepare for it, the better.

【正确答案】 D

【答案解析】[分析]形近识别 A．transmission播送，发射，传输；B．transposition调换，变换；C．transformation变化，转化，改革；D．transition转变，转换，过渡；因此D为答案。