It was said that the Chinese used 
                                their cats as clocks in the days before the invention 
                                of the watch. The pupils of the cat’s eyes were 
                                believed to gradually change ____________ with 
                                the position of the sun in the sky. At midday 
                                they were a narrow line and they gradually became 
                                rounder until sunset. [1점] //1997Q22
                                  ① habit             ② feelings
                                   ③ time              ④ schools
                                   ⑤ shape