A、They could not go on until the ringing stopped. B、They could no longer concentrate on their task. C、They grabbed the phone and

In a recent study carried out by psychologists on the disruptive effects of smartphones, two groups of college students were given word search puzzles. The first group was told to complete the puzzles with its participants’ smartphones in their line of sight. The second group, however, was told that the phones would interfere with the equipment in the experiment, and would need to be moved away from the testing area. Midway through the second group’s solving of the puzzles, the experimenter called one of the phones and let it ring for a while before hanging up. Many of the students in that group were unable to focus from then on, becoming anxious and performing more poorly than the first group.
   Use of electronics has also been known to lead to a decline in human interactions. Rather than having real-life conversations, many express emotions and engage in deep conversations through social media sites. Many students use their phones and computers during class for non-academic activities, which leads to poor grades. Perhaps the most dramatic impact is the reduction in the amount of sleep, which leads to poor health and weight gain.
   Technology is a great tool; however, it’s important to recognize its downsides. Lack of sleep, reduction of productivity and weight gain are only a few. If we’re not careful about all these minor problems right now, the effect on the future generation is going to be much bigger.
   Questions 22 to 25 are based on the passage you have just heard.
   22. What were the college students in both groups required to do in the study?
   23. What do we learn about many of the students in the second test group after the phone rang?
   24. According to the passage, what is the most dramatic impact of smartphone use?
   25. What does the speaker suggest people do?