单选题 By the relation of______one means that different sets of clauses may permit of require the occurrence of a word of another set or class to form a sentence or a particular part of a sentence.
【正确答案】 C
【答案解析】解析：考查共现关系。共现关系是指不同词类的不同词汇集合，允许另一个词类或集合的词出现，构成一个句子或句子的某一特定部分。