以下各生态系统中，自动调节能力最弱的是（ ）

根据短文内容，选择正确的答案。

Alice, 35

    I like shopping, but shopping with young children is not an easy thing. I have to look after them while I'm shopping. Shopping with my husband is not fun, either(也). I only go shopping with my husband when I need to buy something for him. If I look at a dress for myself, he says something like “The dress is too big” or “You don't need to buy that now”. I often go shopping with my friends. It's fun. I like shopping alone(单独) too.

Maria, 26

    I like shopping very much, but I never go shopping at weekends. There are too many people in the shops. I don't like shopping with other people. It usually takes me a lot of time to choose things because I never buy the first things I see. I always look around other shops to find the best price. I'm good at finding the best deals(商品). I don't like buying food in small shops and street markets(市场). I think food in the supermarket is fresher and cheaper, so I shop there.

    I have a good friend，Joanna．I  ____her well．She is a nice girl but she is not very ____．You can see books, pens and notebooks are ____ in her room．In the school, she always asks．" ____is my pen? Where are my books? And where are ．．．?" I often ____her．This morning, Joanna can't ____her English notebook， and she ____find it．so she asks me to help her．

某人骑自行车在平直道路上行进，图中的实线记录了自行车开始一段时间内v﹣t图象，某同学为了简化计算，用虚线作近似处理，下列说法正确的是（   ）