儿童常常用“球球”表示“这是一个球”“我要球球”等，这说明他们的语法发展阶段处于(    )。（易混）

Passage 1    It's one of our common beliefs that mice are afraid of cats. Scientists have long known that even if a mouse has never seen a cat before, it is still able to detect chemical signals released from it and run away in fear. This has always been thought to be something that is into a mouse's brain.    But now Wendy Ingram, a graduate student at the University of California, Berkeley, has challenged this common sense. She has found a way to "cure" mice of their inborn fear of cats by infecting them with a parasite, reported the science journal Nature.    The parasite, called Toxoplasma gondii, might sound unfamiliar to you, but the shocking fact is that up to one-third of people around the world are infected by it. This parasite can cause different diseases among humans, especially pregnant women-it is linked to blindness and the death of unborn babies.    However, the parasite's effects on mice are unique. Ingram and her team measured how mice reacted to a cat's urine (尿) before and after it was infected by the parasite. They noted that normal mice stayed far away from the urine while mice that were infected with the parasite walked freely around the test area.    But that's not all. The parasite was found to be more powerful than originally thought-even after researchers cured the mice of the infection. They no longer reacted with fear to a cat's smell, which could indicate that the infection has caused a permanent change in mice's brains.    Why does a parasite change a mouse's brain instead of making it sick like it does to humans? The answer lies in evolution. "It's exciting scary to know how a parasite can manipulate a mouse's brain this way," Ingram said. But she also finds it inspiring. "Typically if you have a bacterial infection, you go to a doctor and take antibiotics and the infection is cleared and you expect all the symptoms to also go away." She said, but this study has proven that wrong. "This may have huge implications for infectious disease medicine."
Which of the following statements is true according to the passage?

第一次使用“思想路线”这一概念的是毛泽东。（  ）

关于分层随机抽样的特点，表述正确的是（　　）。

下列各项，不需重按才能察到的脉象是

下列关于个人汽车贷款信用风险管理措施的表述中，错误的是（  ）。

胎儿血液循环中 ，血氧饱和度最低的部位是

根据《中华人民共和国消费者权益保护法》，甲药品零售企业出售西洋参片短斤缺两，该行为侵犯了消费者的（）

女，48岁。因持续胸痛10小时收入院。查体：血压117/78mmHg，高枕卧位，双肺可闻及较多细湿啰音，啰音范围大于1/2肺野。心电图示：V₁~V₄导联ST段抬高0.2～0.4mV。该患者的心功能分级是（   ）。

(   )是角色游戏结构要素中最核心的要素，它统帅着其他结构要素。

出现大便隐血试验阳性，其上消化道出血量至少达到的数量是