40 What can be inferred from this passage?
(A)Students who have math anxiety should not be forced to take math classes after middle school.
(B)Math aptitude can be accurately determined before middle school.
(C)Students should learn math as much as possible whether they like it or not.
(D)Students usually do not feel threatened by math before the age of 12.

By about age 12, students who feel threatened by mathematics start to avoid避開 math courses, do poorly in the few math classes they do take, and earn low scores on math-achievement成就，成績；功績 tests.

Some scientists have theorized建立理論 that kids having little math aptitude天資 in the first place justifiable無可非議 read grappling with盡力解決（grapple翻譯：（尤指為了得到某物而）扭打，搏鬥）numbers.

However, it is not that simple, at least for college students, according to a study in the  journal雜誌，期刊、日記（補充：journey翻譯：（尤指搭乘交通工具的）旅行，行程, 旅行。）of Experimental（尤指科學方面）實驗 Psychology.

According to the study, people’s intrusive打攪 worries about math temporarily disrupt打斷 mental processes needed for doing arithmetic算術 and drag down math competence能力, report Mark H.

Ashcraft and Elizabeth P. Kirk, both psychologists at Cleveland(Ohio) State University.

Math anxiety exerts使用, 運用 this effect by making it difficult to hold new information in mind while simultaneously同時 manipulating it, the researchers hold.

Psychologists regard考慮，思考；將…認為；看待 this capacity數量, 容積, known as working memory, as crucial關鍵 for dealing with numbers.

“Math anxiety soaks up吸收 working memory resources and makes it harder to learn mathematics, probably beginning in middle school,” Ashcraft says.