21-25為題組
         According to a recent study, the world’s 3.5 billionsmartphone users may be at risk of long -term neck and back pain.Frequent use of smartphones, tablets, and laptops __(21)__ stresson the spine and alters the natural curve of the neck. These physicalrisks are especially high for young people, who have experiencedneck pain earlier __(22)__ previous generations. What can bedone to relieve neck pain and avoid muscular disord ers that __(23)__ long hours of smartphone or tablet use? Asking people to reducedevice usage may not be realistic, __(24)__ developing good posture habits can certainly help. Keep the screenof your device at eye level __(25)__ you can keep your neckfrom leaning forward. If this is too tiring, try looking down with justyour eyes instead of bending your head forward. Tech breaks are alsoimportant — just a few 2-3 minute breaks every hour can make a bigdifference.
【題組】21.
(A) runs
(B) puts
(C) manages
(D) reduces