【题目】Being kind to others should be everyone's ________of behavior；________，our world will be more peaceful and beautiful.
A．aim；if so
B．standard；if that
C．belief；even so
D．principle；if so
在线课程【答案】D
【解析】考查名词与省略。principle of behavior“行为准则”；if so“如果那样的话”。