女性，67岁，近1年来感头晕、乏力、记忆力减退、面色苍白；因急性阑尾炎手术治疗，术后

小儿皮质下中枢的兴奋性较高，但皮质发育未完善，对皮质下中枢不能控制，所以它的兴奋和抑制过程容易扩散，这就可以解释为什么婴幼儿遇到强烈刺激时，容易发生

A．腹泻

B．惊厥

C．呕吐

D．睡眠

E．发热

从该B树中删除关键码15后，该B树的第2层的结点数为

A．6

B．7

C．8

D．9

Mr Jones was purchasing items to furnish his new house. He ordered all electrical and plumbing fi ttings from one supplier and these included an air-conditioning system. After being installed it transpired that the system could only provide cooling and no heating. Mr Jones is claiming that this is not what he ordered and that the supplier should replace the system provided and return the payment effected for the air conditioning system.Required:Explain what action, if any, can be taken against the supplier by Mr Jones. (10 marks)

一位母亲带了一个1岁的正常男孩进行体格检查，测得的头围应该是（）

A.38cm

B.40cm

C.46cm

D.48cm

E.50cm

小杆线虫正常的居住地是土壤，但有时会偶然潜入人体，并在人肠中找到有利的生存环境，这种寄生虫是（）

A.半寄生

B.专性寄生

C.兼性寄生

D.社会性寄生