单选题 Current data suggest that although ______ states between fear and aggression exist, fear and aggression are as distinct physiologically as they are psychologically.
A. simultaneous B. serious C. partial D. transitional

【正确答案】 D
【答案解析】D项的industrious“过渡的”符合题意。simultaneously同时发生；serious严厉的，严重的；partial部分的，不公正的，都与题意不符。