在解分式方程 $\frac{2}{x+1}-\frac{3}{x-1}=\frac{1}{x^2-1}$ 时，小明的解法如下：

解：方程两边同乘以（x+1）（x﹣1），得2（x﹣1）﹣3=1①

去括号，得2x﹣1=3﹣1   ②

解得x= $\frac{5}{2}$

检验：当x= $\frac{5}{2}$ 时，（x+1）（x﹣1）≠0  ③

所以x= $\frac{5}{2}$ 是原分式方程的解  ④

选出在意义上属于不同类的图片。

    There is an old English saying, "Laughter is the best medicine." One person certainly would have agreed with this is Norman Cousins.

    Norman Cousins was the editor of a magazine called Saturday Review for almost forty years. He also 1 and spoke about world peace and anti-war issues(反战议题), traveling to many different countries to share his 2.

    In the 1960s, after returning to the United States from a busy and tiring trip to Europe. Mr. Cousins got 3. He discovered he had a strange disease that caused great pain in his bones(骨头).

    In less than a week after he got back, he could not 4 it. Every move that he made was painful. He was not able to 5 at night. The doctor told Mr. Cousins that they did not know how to cure (治疗)his problem and he might never 6 the illness. Mr. Cousins, however, refused to give up hope.

    Mr. Cousins thought that the illness could be caused by 7 thoughts. He did not want to take 8 to cure himself. Instead, he felt that happy thoughts or laughter might cure his illness.

    He began to experiment on himself while still in the hospital by watching comedy shows on television. Mr. Cousins quickly found that ten minutes of 9 laughter during the day gave him two hours of pain-free sleep at night.

    Deciding that the 10 could not help him, Mr. Cousins left the hospital and checked into a hotel room where he could 11 his experiments with laughter. For eight days, Mr. Cousins 12 in the hotel room watching comedy shows on television, reading amusing books, and sleeping whenever he felt 13. Within three weeks, he felt well enough to take a vacation to Puerto Rico where he began running on the beach for 14.

    After a few months, Mr. Cousins was 15 to carry on his work. He had laughed himself back to health.

用显微镜观察小鱼尾鳍内血液的流动时，辨别毛细血管的依据是（    ）