Some people don’t like doing sports because they think it is hard work and will make____ (他们) feel tired . That’s wrong! Sports help us to____ (保持)healthy , happy and live longer .If you____ (从不) do sports , you will get unhealthy easily . Sports are____ (也)a good way to make friends .People from different____ (地方) may not know each other , but after a game , they often become good friends .And sports in winter and ____ (夏天)are not the same.____ __(swim) is fun in hot weather , while skiing is great____ cold days . Many people____ (享受) watching others play games .They often get very____ (兴奋) when “their” players or teams win .

读课文《“没头脑”和“不高兴”》，按照故事发展的起因、经过、结果，把课文分成三部分

如图，正三角形△$A_1{B}_1{C}_1$的面积为1，取△$A_1{B}_1{C}_1$各边的中点$A_2$、$B_2$、$C_2$，作第二个正三角形△$A_2{B}_2{C}_2$，再取△$A_2{B}_2{C}_2$各边的中点$A_3$、$B_3$、$C_3$，作第三个正三角形△$A_3{B}_3{C}_3$，…用同样的方法作正三角形，则第2个正三角形△$A_2{B}_2{C}_2$的面积是____ ，第10个正三角形△$A_{10}{B}_{10}{C}_{10}$的面积是____  .