When a firm is earning positive economic profits in a monopolistic competitive market, what will most likely occur
A. New firms will enter driving down the economic profits to zero.
B. Losses will occur in the short run.
C. Price takers will be over run by price searchers.
查看答案
Which of the following statements regarding monopolies is FALSE
A. Monopolists will try to get favorable treatment from the government called rent seeking.
B. Due to the law of diminishing returns, natural monopolies exhibit an upward sloping average total cost curve.
C. Inefficient producers are able to survive.
Which of the following is least accurate regarding the allocative efficiency associated with price discrimination Price discrimination:
A. results in gains to the discriminating firm by selling to consumers with relatively inelastic demand.
B. increases production closer to the quantity where price equals marginal cost.
C. leads to a decrease in allocative efficiency.
女，14岁。偶然发现右下后牙颊侧牙龈有小脓包前来就诊。检查：右下第二前磨牙畸形中央尖折断。Ⅰ度松动，颊侧牙龈有窦道口，X线片见根长为9mm。根尖呈燕尾状敞开，根尖周X线透射区4 mm×5mm，边界模糊不清，该主诉牙的治疗应选用
A. 根尖诱导形成术
B. 塑化治疗
C. 干髓治疗
D. 根管治疗
E. 拔除
患儿，7岁。主诉左下后牙有龋洞，冷热疼痛，无自发疼。查：左下6深龋洞，叩诊(－)，牙龈正常。X线片示牙根未形成，未见病变。处理：去除大部分腐质，近中髓角去腐时穿髓1mm穿髓孔探疼，应选何种治疗方法
A. 活髓切断术
B. 直接盖髓术
C. 拔髓术
D. 尖诱导成形术
E. 封金属砷后根管治疗
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