老师要求学生写一个“已知一正项数列{a_n}，满足a₁=1，a₂=1，a_n=a_n﹣1+a_n﹣2（n≥3，n∈N），计算a_n．”的算法框图．右图是王华同学写出的框图，老师检查后发现有几处错误．其错误的序号是____（写出所有错地方的序号）．

下列表述正确的一项是(　　)

如图为人体内气体交换的过程，分析图解并回答下列问题．

有5名优秀毕业生到母校的3个班去作学习经验交流，则每个班至少去一名的不同分派方法种数为（　　）

阅读短文，下列问题

  Solve equations(方程式)and fun number problems with this online Maths game for kids. Understand how to do mental (只在心里做的) Maths, train your brain to handle (处理) numbers and improve your problem solving skills.

    If you want to improve your multiplication skills, then give this great activity a try.

    Follow the instructions and solve a range of interactive multiplication problems that are perfect for kids.

    Check out this cool division game for kids. Have fun improving your math skills with a variety of interactive challenges.

    Click on the flashing signs as they show the correct answer, watch carefully and don't click on the signs too early, can you finish them all?

    This place value game for kids helps children understand how units of numbers work.

    Complete fun activities, number problems and simple equations while learning about tens, hundreds and thousands.