患者右下第一前磨牙及右上第一，第二磨牙残根，既往曾有风湿性心_爱下问搜题

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问题单项选择题

患者右下第一前磨牙及右上第一，第二磨牙残根，既往曾有风湿性心脏病史10余年，现存在二尖瓣狭窄，心功能Ⅰ级

对此患者施行牙拔除术时须慎重，否则容易引起的严重并发症是

A．颊间隙感染

B．颌下间隙感染

C．干槽症

D．败血症

E．亚急性细菌性心内膜炎

答案

参考答案：E

解析：对此患者施行牙拔除术时须慎重，否则容易引起的严重并发症是亚急性细菌性心内膜炎。

报关编码

2,4-二氨基甲苯

单项选择题

Microwave communication uses high-frequency (71) waves that travel in straightlines throughthe air. Because the waves cannot (72) with the curvature of the earth, they can be (73) only over short distance. Thus, microwave is a good (74) for sendingdata between buildings ina city or on a large college campus. For longer distances, the wavesmust be relayed by means of"dishes" or (75) . These can be installed on towers, highbuildings, and mountain tops.

A．transmitted

B．transformed

C．converted

D．delivered