如图是在显微镜下观察到的人血涂片示意图．下列是某同学对图中的血细胞所作的描述，你认为最恰当的是（　　）

①中学时代是人生发展的一个新阶段

②中学时代为我们的一生奠定重要基础

③中学时代只有苦恼没有快乐

④从中学时代才开始主动发现和认识自己

阅读短文，回答问题。

Bear Amy,

   I want to be your friend. Let me introduce my family to you. My father is a doctor. He is tall and strong. My mother is a teacher. She is think and kind. My brother Sam is 6 years old. He's short and funny. We live in a big city. However, we usually go hiking on the weekends. I have a small and nice room. There is a bed and a desk in my room. I like reading books. I have many books on my desk. Welcome to my home.

                                                                                                                                                                        Yours,

                                                                                                                                                                          Lucy