The writer wants to add a sentence after sentence 1 to provide factual support for the introductory claim and focus the audience on the argument of the passage А
Thanks to a process called neuroplasticity, the brain continually strengthens or weakens neural connections in response to stimuli from smartphones,
B
Researchers at Columbia University argue that "[w]e are becoming symbiotic with our computer tools, growing into interconnected systems that remer
с
According to a recent Gallup Poll, only 21 percent of Americans say they "rarely" or "never" feel mental or emotional strain in their day-to-day lives.
D
A recent study found that 86 percent of Americans are stressed out from constantly checking their smartphones.
Neuroscientist Susan Greenfield cautions that social media can become a platform for constructing an artificial identity to impress an audience of harah

its A

Explanation:

minutes, according to brain scans, the babies had learned to tense their eyelids when they heard the

tone.

(12) Not only are babies’ brains too busy during REM sleep to dream, says Foulkes, but they also lack the

ability to imagine things visually, a skill necessary for dreaming. (13) In fact, according to his research,

children don’t start dreaming until they are four or five years old, and even then, the dreams lack the vivid

details and structured story lines that characterize adult dreams.

(14) For example, sometimes parents claim that they have witnessed their toddlers having terrible

nightmares, which can be more frightening for the parents than for the toddlers. (15) Furthermore, it is

only when children develop strong self-awareness, typically around age seven or eight, that they begin to

place themselves in their dreams and have dreams with clear narratives. (16) Babies, Foulkes argues,

are nowhere near that level of cognitive development.