We often find that weekends and holidays feel so short while classes and work feel so long. In reality, though, we know that this is not true. But we still wonder where that strange feeling comes from. In fact, this is one of the ways that we're tricked by time, according to the website All That Is Interesting. The website lists several wrong impressions we often have about time. Let's have a look. First of all, emotions affect our time-keeping abilities: Negative emotions, especially anxiety and boredom, make time seem longer because they make us concentrate more on the passage of time. However, when we are enjoying ourselves, we pay more attention to what we are doing and are likely to lose track of(...) time. Here is another example. In 2007, a group of scientists carried out a test. In the test, people fell 50 meters into a safety net and were then asked about their experience. Although the experience took shorter than 3 seconds, the people thought it was much longer than it actually was. This is because of the way our bodies reply to danger, according to the scientists. Our bodies produce a chemical called adrenaline  when we are faced with danger. It allows us to concentrate better so that we can stay alive. As a result, we are able to remember far more details over a short period of time, which makes it seem like time is going more slowly. Another occasion when we make mistakes about time is when we take afternoon naps . Have you ever had trouble telling what time it is after a long nap? That's because the best amount of time for a nap is 20 minutes. After 20 minutes, you enter a new stage of sleep called slow-wave sleep. If you wake up mid-way in this stage, it will take a while before you can correctly perceive  time again. Yes, time can be mysterious and there is no way to control it So, perhaps the best thing to do is to make good use of every minute. When people feel that an experience is longer than it really is,   _  .
a chemical called adrenaline is playing a role they are concentrating on what they are doing they are responding faster to the changes around them they could be facing danger or feeling bored
Question: We often find that weekends and holidays feel so short while classes and work feel so long. In reality, though, we know that this is not true. But we still wonder where that strange feeling comes from. In fact, this is one of the ways that we're tricked by time, according to the website All That Is Interesting. The website lists several wrong impressions we often have about time. Let's have a look. First of all, emotions affect our time-keeping abilities: Negative emotions, especially anxiety and boredom, make time seem longer because they make us concentrate more on the passage of time. However, when we are enjoying ourselves, we pay more attention to what we are doing and are likely to lose track of(...) time. Here is another example. In 2007, a group of scientists carried out a test. In the test, people fell 50 meters into a safety net and were then asked about their experience. Although the experience took shorter than 3 seconds, the people thought it was much longer than it actually was. This is because of the way our bodies reply to danger, according to the scientists. Our bodies produce a chemical called adrenaline  when we are faced with danger. It allows us to concentrate better so that we can stay alive. As a result, we are able to remember far more details over a short period of time, which makes it seem like time is going more slowly. Another occasion when we make mistakes about time is when we take afternoon naps . Have you ever had trouble telling what time it is after a long nap? That's because the best amount of time for a nap is 20 minutes. After 20 minutes, you enter a new stage of sleep called slow-wave sleep. If you wake up mid-way in this stage, it will take a while before you can correctly perceive  time again. Yes, time can be mysterious and there is no way to control it So, perhaps the best thing to do is to make good use of every minute. When people feel that an experience is longer than it really is,   _  .
A. a chemical called adrenaline is playing a role
B. they are concentrating on what they are doing
C. they are responding faster to the changes around them
D. they could be facing danger or feeling bored
Answer: