symbol.sign.singal.mark四个词的区别

symbol.sign.singal.mark四个词的区别 mark symbol sign signal四个词的区别? sign,symbol,mark,feature做“标记象征特征”时四个词的区别 mark symbol sign signal这几个词的区别. mark symbol sign signal这几个词的区别是什么? example ,sign ,mark ,symbol的区别 symbol,sign,signal,mark区别有哪些?好懂点的 sign & symbol的区别? sign signal symbol的区别 sign,symptom,symbol的区别 logo symbol sign 的区别 高一英语词义辨析求sign,mark,symbol的区别