第20题: [单项选择]It is ______ in Western countries to give people gifts on their birthdays. A. coherent B. customary C. cooperative D. cumulative 参考答案:B 答案解析:[解析] 形容词辨义。这四个选项的词性都是动词,其中coherent表示“粘在一起的;连贯的;一致的;符合的”,customary是指“通常的;习惯的;惯例的”,cooperative表示“合作的;愿