是什么东西能在同一时刻使一个民族成千上万的成员形成某种差不多一致的行为倾向呢?这种东西只能是一种可以同时在千千万万民族成员中间潜移默化地相互感应、相互影响的心灵深处的东西，一种看不见摸不着的、属于精神上的、属于人们心灵的东西——民族精神。始终鼓舞我们民族迎难而上、团结互助、战胜敌人与困难的不竭力量之源是(     )

用方框中所给单词的适当形式填空，每空格限填一词，每词只能填一次。

    Good habits are important to us. We should build good living habits. Now let's have a look at the two brothers. Li Qiang and Li Gang are brothers. But their living habits are different. Now let's go to Li Qiang's room. Li Qiang cleans his bedroom every day and puts his things away. Look! There is a computer on the desk. There are two balls under the bed. A guitar and a kite are on the wall. Some books are on the shelf. So he must be a careful boy. Now let's go to Li Gang's room. The room is not clean. Can we see his clothes on the desk? Oh, yes. We can see a football and a knife on the desk, too. Li Gang never does any cleaning on weekends. So his room is in a mess.

    What do you think of Li Qiang and Li Gang? Li Qiang is a good boy. Li Gang must learn from his brother