Question

questions 14 through 18 refer to the following.
(the passage below is a draft.)
(1) people who learn another language as kids can sound like native speakers, but adult
language learners often make noticeable grammatical mistakes. (2) but when exactly in a
persons life does it become difficult to master the rules that govern a language? (3) while
previous theories speculated that people can only acquire a new language at a young age,
new research supports a different perspective.
(4) boston-area researchers found evidence that the time span for language acquisition
lasts from infancy until early adulthood; this time span is known as the \critical period.\ (5)
such a period also exists for the development of eyesight. (6) prior studies had reached
varying conclusions about the critical period: it closes just after birth; it stops around age 5,
it lasts until age 13. (7) dissatisfied with these studies, small number of participants, the
boston researchers aimed for a large sampling of language users for a study of english
grammar acquisition. (8) the researchers developed an online grammar quiz with follow-up
questions about the quiz takers language background. (9) getting nearly 700,000
responses, two-thirds from nonnative english speakers, the research team mapped the
relationship between age and language fluency in detail.
(10) the accuracy of answers to the questions on the grammar quiz plummeted for those
who began learning english after age 17. (11) though this result indicates that the critical
period for language acquisition lasts longer than previous studies suggested, the
achievement of native-speaker-level fluency is out of reach for adult learners.

14 mark for review
the writer wants to add a sentence that introduces the topic of the passage. which of the
following sentences, if added to the beginning of the first paragraph, would most effectively
accomplish this goal?
a language experts have long observed that children are better
than adults at mastering a second language.
b scholars and journalists continue to debate whether studying a
foreign language in college has any intrinsic value.
c the development of young childrens brains is influenced both by
childrens experience with their caregivers and by genetic factors.
d being able to express ones thoughts in grammatically correct and
reasonably eloquent sentences during job interviews can

Explanation:

The passage is about language learning and the critical period. Option A directly relates to the main topic of children being better language - learners (as the passage discusses people learning another language and the critical period for language acquisition). Options B, C, and D are either off - topic (like college foreign language having no intrinsic value in B, genetic factors in C which is not the main focus, and expressing thoughts in interviews in D) or less relevant compared to A which sets up the discussion about children and language learning as in the passage.

Answer:

A. Language experts have long observed that children are better than adults at mastering a second language.