Answer:
Tan gives an example of her experience with achievement tests to support the idea that they are not always accurate measures of language ability.
Step-by-step explanation:
In this excerpt from "Mother Tongue" by Amy Tan, the author builds a central idea of her story because she gives an example of her experience with achievement tests to support the idea that they are not always accurate measures of language ability. According to Amy Tan, the way a person speaks is not an accurate measure of the person's intelligence. She got no good results in achievement tests but she became a major in English in her first year of college.