盐酸肾上腺素适用于心脏骤停患者，主要因为其具有()A．β肾上腺素能受体激动剂的特性

短文改错/Proofreading and error correction

It was the chance of a lifetime to win the first prize on the Story Writing Show. All I had to do was to write a story or present it. My teachers have been telling me how great my writing was. So if they had said was true, I would have a chance of winning the prize. What were better, I had useful help. There was Uncle Chen, gentleman living near my house, who was a very much famous writer. He agreed to reading my story and give me some advices on how to write like a real writer.

1（）

X、Y、Z在同一短周期，X、Y、Z分别易形成X^-、Y⁺、Z²⁺离子，它们半径之间存在的关系是[ ]

A．X>Y>Z

B．Y⁺>Z²⁺>X^-

C．Y⁺>X^->Z²⁺

D．X^->Y⁺>Z²⁺

铅中毒实验，选用大鼠复制动物模型时，大鼠本身易患进行性肾病，容易与铅中毒所致的肾病相混淆，选用蒙古沙鼠则较好，因为蒙古沙鼠只有铅中毒才会使其出现肾病变。此符合（）模型评估原则。

A、重复性

B、相似性

C、可靠性

D、可控性

患儿8岁，前牙深覆抬，第一恒磨牙萌出2/3，该阶段预防及治疗的重点应该是

A．第一乳磨牙

B．第二乳磨牙

C．尖牙

D．第一恒磨牙

E．上颌切牙

完整的汽车销售流程由几个主要环节组成？