阅读下面的材料, 在空白处填入适当的内容（一个单词）或括号内单词的正确形式填空。
Encouragement is necessary for humans to develop and work hard. It helps people keep going. Here is a story of a simple note of praise. This note helped many people understand the ____ (important) of giving praise to other people.
Robert Brooks is a psychologist (心理学家) now. He remembers the time when he was just a young man. He was in training to be a psychologist. He had to give a ____ (speak) in front of a large group of people. And, he was very nervous. He did not like speaking in front of people. But his speech was very important.
Robert gave his speech. He did a good job. But he did not have the chance to hear ____ other people thought. Later that same day Robert looked into his mail box and ____ (find) a small note there. The note ____ (simple) said, "You did a great job today, Robert." Robert was very surprised and happy to see the note. It made him feel very good. And, Robert believes that that small note helped him through the rest of ____ (he) training. He felt like he was able to do a good job.
Now ____ a psychologist, he teaches people how important it is to give praise to other people. He tells them the story of the simple note that he received. He tells them that the words on the note had power. Those words helped him to continue doing a good job. One day, a businessman, who had ____ (attend) Robert's lecture, decided to take Robert's ideas to heart.
The more this businessman encouraged his workers, the ____ (happy) they were. "The atmosphere in our company changed. We enjoyed working. We began to encourage each other too," said one of the ____（worker）. "People seemed happier. But, most important of all, a greater spirit of team work developed," the businessman added.
