When we say the "mouth" of a river, we associate the opening par

When we say the "mouth" of a river, we associate the opening part of the river with the mouth of a human being or an animal. In this sense, the word "mouth" conveys ______.
A、onomatopoeic motivation
B、morphological motivation
C、semantic motivation
D、etymological motivation
【正确答案】：C
【题目解析】：本题考查第五章理据中拟声理据、形态理据、语态理据和词源理据的概念理解和辨析。语态理据semantic motivation是解释单词字面意和比喻意之间的联系。题目中河口会联想动物或人的口，因此选择C．