阅读下列短文,从每题所给的A、B、C和D四个选项中，选出最佳选项。
A
In early 2021, I hit a rut in my studies. Although I had been productive early in my graduate career, my long hours and hard work were no longer translating into success in the laboratory, and I felt hopeless about achieving my goals.
As I began to search for the cause of my struggles, I became increasingly aware that my “quiet time” at the lab bench was anything but. Instead of thinking about science, I was watching television or interacting with social media on my smartphone. Although I could mask this inefficiency (低效率）with longer hours, my work felt disorganized. Through reflection, I came to understand my problem.
To make a change, I reduced my connectivity by using a basic mobile phone without an Internet connection during work hours, and removing unnecessary apps from rn> smartphone when I did use it. Things didn’t go smoothly in the beginning, but with time, started reading papers during long experiments, and began a habit of writing in my do time. These practices have already yielded success: I am currently preparing a review article for publication with my adviser. I have also felt more engaged in meetings — coming better prepared, asking questions and taking hand-written notes. Perhaps most importantly, I have felt my anxiety about work efficiency disappear and that my disorganized work-life relationship is traded for one with clearer boundaries.
Changing my smartphone habits has also created challenges. Not all my friends have been supportive of my reduced connectivity, and I have missed messages on communication services. Yet these problems have been a small price to pay for increased productivity. So if you find yourself in this situation, I encourage you to build down time and uninterrupted study into your schedule, which could be significant for your success.
21. What does the underlined expression “my ‘quiet time’ at the lab bench was anything but” mean in Paragraph 2?
A. Screen time took up too much of my work hours.
B. I was busy in reflecting on my work inefficiency.
C. I always had a good rest quietly at the laboratory bench.
D. Watching TV on my phone is always my choice during a break.
22. According to the author, what is the major benefit of changing smartphone habits?
A. Enough time to read papers.
B. A good balance between work and life.
C. The Ability to publish scientific articles.
D. More chances to attend important meetings.
23. What can be learned from the last paragraph?
A. A full schedule for study is important in determining peopled career.
B. The author’s friends didn’t support his decision on smartphone usage.
C. Missed messages on communication apps didn't cause trouble to the author.
D. It is worthwhile to reduce the connectivity on smartphone despite challenges.
24 From the passage we can know that the author ___________.
A. cared about what others said very much
B. chose to abandon his smartphone to make a chang
C. hoped to help others by sharing his own experience
D. many times to improve his work effidency but faded
