阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中， 选出可以填入空白处的最佳选项。
John graduated from a key university and he was very good at his major. He wished to find a good job. One day, he went to a company to 1 for a job. He got the news in a newspaper. He did some research on this company. When he was 2, everything went well. The manager asked him some questions and he answered them 3. John was very satisfied with his performances and was very 4 that he could get the job. But at that moment, the manager's phone 5. He picked up the phone, listened and nodded. And then he turned around and said to John, “Sorry, I want to get some important 6 now. Please give me the book with the red 7 on that desk.” John looked around and found 3 books on the desk, so John went to the desk, took one book and handed it to him 8. Holding the book, the manager 9 the phone and said, “Sorry, we cannot give the job to you.” John was 10 and wondered why. The manager said, “There are three 11. First, when you came into the office room, I found that the third button on your shirt had been missing. Second, there are three books with red covers on that desk, but you didn't ask me which one I needed and you took one randomly（随机地）. Third, I was answering the call. You should 12to the desk to save time. These 13 showed you are not a careful person.”14, John didn't get the job.
We can learn a(n) 15 from John's experience. Some people don't 16the details in our life. But it is the details that 17. Not only should we value what we learn but also we should pay more attention to the details. Sometimes they can even 18 our success or failure. We should form the habit of being careful and learn to keep the 19 of quantity and quality. We should keep it in mind that 20 comes first, without which quantity is of no significance.
