A few months ago, I was picking up the children at school. Emily, another mother that I knew well, rushed up to me. She was full of 21 . “Do you know 22 you and I are?” she asked. 23 I could answer, she gave out the reason for her question. She had just returned from renewing her driver’s license at a government office. The woman 24 desk asked her what her “occupation” was. Emily hesitated, 25 how to answer it. “What I mean is,” explained the woman, “do you have a job, or are you just a ...?” “Of course I have a job4.如图甲、乙、丙分别表示在有限空间内培养(或饲养)两种生物的实验结果,下列相关的叙述错误的是( )A.豆科植物与根瘤菌的种群数量变化关系如图甲所示B.甲、乙、丙分别表示的是互利共生、捕食、竞争关系C.图丙中实验初期,竞争与种内互助并存,后期X的种内斗争加剧D.图乙中b生物对a生物的进化有害无益