下列命题中正确的个数是（  ）
①$x^2>4$是$x^3<-8$的充分不必要条件。
②在$△ABC$中，BC为最大边，则“^{$A{B}^2+A{C}^2=B{C}^2$}”是“$△ABC$为直角三角形的充要条件”。
③若$x^2$是无理数，则$x$也是无理数的逆命题.

下图为世界两区域图，其中甲区域在大陆西岸，乙区域在大陆东岸，关于甲、乙两区域社会经济状况的说法，正确的有（     ）

①区域老龄化严重，为人口净迁入区

②乙区域产业结构调整，为人口的净迁出区

③甲区域乳畜业发达，商品率高

④甲区域城市化速度快于乙地

⑤两区域矿产资源丰富，工业发达

⑥两区域水路交通便利，航运发达

    Many students have hobbies, such as reading, painting, growing vegetables in their gardens, and looking after animals. Some hobbies are relaxing and 1 are creative. Hobbies can develop your interests and help you learn new skills (技能). David Smith is a student, and his 2 is writing. During the summer of 2000, he 3 four weeks on a summer camp. As well as the usual activities, such as sailing, climbing and mountain biking, there was a writing workshop with a professional 4. "She asked us to imagine that we were in a story. Then we wrote about our experiences at the camp."

    In senior high school David wrote a story about teenage life, and it came out (出版) 5 a book in 2003. Many teenagers love his book, and as a result, David has become a 6 young writer.

    David has been very lucky 7 his hobby has brought him enjoyment and success, but he is 8 interested in many other things. "I like playing volleyball, too," says David. "I spend some of my free time playing volleyball for my school team. 9 I'll write more books in the future, but I'm not sure."

    It's sometimes difficult 10 that we shouldn't spend all our time on our favorite hobby. There are many other interesting things to do in life, and we should try to do something new or different.