画一画。

①画 ，比  多2个。

②画 ，比  少1个。

③画 ，和  同样多。

    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

把NaOH溶液和CuSO₄ 溶液加入某人的尿液中，微热时，如果观察到红色沉淀，该尿液中含有（　　）