因式分解：x³y﹣xy= ____.

    Sun Li was not happy at school last month.It was not because 1 hated school.It was because of her2.

    Sun studies in Anhui.Her school has a 3 rule about hair：no changing your hair color，no curly hair；boys should have a crew cut (平头)，4 girl's hair can't hang past their ears.

    Sun and the other girls in her class hate the5.They call it “mushroom head (蘑菇头)”.

    Sun's story is not the 6 one. In many other schools，there is also a hairstyle rule. Last week in a school in Beijing，some students were 7 to cut their long hair.

    Mr. Xu is the headmaster of the school. In his school，girls can't have hair past their shoulders (肩膀).He says the hair rule is there for a good 8.“Everybody needs to have a look that matches (与……相配) his or her job，” says Mr. Xu.“Those hairstyles are for adults.Students are 9 from adults.”

    The strict hair rule is not only made for students.Teachers also have to 10 it.“While students can't change their hair color，neither can their teachers. ” says Mr. Xu

工业上制备纯硅反应的热化学方程式如下：SiCl₄(g)＋2H₂(g)  Si(s)＋4HCl(g) △H＝＋QkJ·mol^-1(Q＞0)，某温度、压强下，将一定量的反应物通入密闭容器中进行以上的反应(此条件下为可逆反应)，下列叙述正确的是（      ）