5. The characteristics of microcirculation in late shock stage are: A: A. Increased forward resistance and significantly decreased perfusion and slower blood flow through the capillary network. B: B. Increased rear resistance and significantly increased perfusion and slower blood flow through the capillary network. C: C. The microvessels are paralytically dilated, no perfusion and blood flow through the capillary network. D: D. Continuous spasm and contraction of microcirculation.

Which of the following about ventilation/perfusion ratio is wrong? A: normal value in quiet state is 0.84 B: decreasing of ventilation/perfusion ratio means that the alveolar ineffective cavity increases C: ratio in pulmonary bottom is the smallest D: in pulmonary embolism, the ratio increases

目前磁共振功能成像应用越来越多，下列序列中属于功能成像的方法有 A: MRU B: DWI C: DTI D: MR-Perfusion

一个垄断厂商使（）以最大化利润，对它而言，有（）。因此，它在（）的地方其利润最大化 A: MR>MC,MR B: MR=MC,MR=P,MC=P C: MR=MC,MR D: MR>MC,MR=P,MC

垄断厂商短期均衡时（ ）。 A: MR=SMC B: MR=LMC C: MR=SAC D: MR=LAC

厂商利润最大化原则是（） A: MR〉MC B: MR〈MC C: MR=MC D: MR〉TC

对垄断企业而言，总是有__________。 A: MR>AR B: MR>P C: MR<P D: MR=P

厂商利润最大化的条件是（）。 A: MR>AR B: MR>MC C: MR=MC D: MR

磁介质有三种，用相对磁导率mr表征它们各自的特性时， A: 顺磁质mr >;0，抗磁质mr <;0，铁磁质mr >;>;1 B: 顺磁质mr >;1，抗磁质mr =1，铁磁质mr >;>;1 C: 顺磁质mr >;1，抗磁质mr <;1，铁磁质mr >;>;1 D: 顺磁质mr <;0，抗磁质mr <;1，铁磁质mr >;0

厂商利润最大化的条件是（）。 A: MR＜MC B: MR＞MC C: MR=MC D: MR≥MC