What causes the ambiguity of the sentence ”I like Mary better th

What causes the ambiguity of the sentence ”I like Mary better than Janet"? （ ）
A、Vocabulary
B、Situation
C、Structure
D、None of the above
【正确答案】：C
【题目解析】：I like Mary better than Janet.这个句子其实是一个省略句，根据语法结构，它可以理解为：1) I like Mary better than I like Janet “我喜欢玛丽多过我喜欢珍妮特” 或是2) I like Mary better than Janet likes Mary."我喜欢玛丽的程度比珍妮特喜欢玛丽的程度更深"。所以这句话的歧义是由语法结构引起的，所以选C。