绝大多数鸟类都能在天空中自由飞翔，这与它们的身体构造息息相关，人类就是从它们那里得到启发来制造飞机的．请回答下面的问题：

    There are over 800 boarding (寄宿) schools in the UK with students from home and foreign countries. Boarding schools started hundreds of years ago in the country. But the earliest boarding schools were set up for white, rich boys only. Now both boys and girls can go to boarding schools from the age of 7 to 18.

    In the UK, boarding schools have three terms in a school year, with about 13 weeks in each term. Students study and live together. They can't go outside if they are not allowed to. In some schools, each student has his or her subject plan. Besides the usual classrooms and laboratories, the boarding schools have lots of other facilities for their students, including music rooms, boats, swimming pools, cinemas and theatres. Most boarding schools have a “light out” time. So when it's time to go to bed, all the lights in the bedrooms are turned off. There are house-masters to take care of students all the time, especially after school hours.

    Nearly all students at boarding schools wear a school uniform. Boys usually wear a shirt and a tie, and girls wear a white blouse, sometimes also a tie and a skirt. As students get older, the rules become less strict.

    In the UK, boarding schools provide students with delicious food. They can choose to have a full English breakfast or simply bread. For lunch and supper, they can choose a meal with or without meat. And there is always self-service for salad and dessert. Students can also make themselves something to eat at any time in a kitchen, or drink tea or have a snack between meals.

①AD是△ABC的角平分线，则∠{#blank#}1{#/blank#}=∠{#blank#}2{#/blank#}= {#mathml#}$\frac{1}{2}${#/mathml#} ∠{#blank#}3{#/blank#}，

②AE是△ABC的中线，则{#blank#}4{#/blank#}={#blank#}5{#/blank#}= {#mathml#}$\frac{1}{2}${#/mathml#} {#blank#}6{#/blank#}，

③AF是△ABC的高线，则∠{#blank#}7{#/blank#}=∠{#blank#}8{#/blank#}=90°．

与其飞行生活没有直接关系的是（　　）