Both bus and tree topologies are characterized by the use of multipoint (1).For the bus, all stations attach, through appropriate hardware (2) known as a tap, directly to a linear transmission medium, or bus. Full-duplex operation between the station and the tap allows data to be transmitted onto the bus and received from the(3). A transmission from any station propagates the length of the medium in both directions and can be received by all other (4). At each end of the bus is a (5) , which absorbs any signal, removing it from the bus.空白(4)处应选择()
A. routers
B. stations
C. servers
D. switches
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男性,17岁,近半月低热37.8C,讲话含糊,情绪易激惹,对父母态度粗暴,有时打骂,胡言乱语,自笑,乱窜病室,抽搐一次,有二便失禁。躯体检查:T37.5C,P100次/分,BP140/90mmHg。下肢肌张力增高,右侧巴氏征(+),克氏征(-)。CSF:潘氏阳性,精神检查:意识模糊,表情呆滞,言语减少,偶有一言半语,称父母是“后爹娘”,无故自笑。头部CT正常,脑电图示弥漫性δ波以额颞为主,有阵发性尖波发放。该患者最可能的诊断是()
A. 病毒性脑炎所致精神障碍
B. 精神分裂症
C. 脑肿瘤所致精神障碍
D. 癔症
E. 癫痫性精神障碍
男孩,3岁6个月,因发热18小时,伴皮疹1小时入院,病程中呕吐3次,伴神萎、尿少,于1月20日入院,查体:T39.5℃,BP68/30mmHg,嗜睡状,面色青灰,唇周发绀,心率128次/分,心律齐有力,双肺呼吸音清晰,腹不胀,软,无压痛,臀部及下肢见散在瘀斑、瘀点,以臀部为主,四肢膝关节、肘关节以下凉,见大理石花纹,颈阻力(+),布氏征(-),克氏征(-),巴氏征(-)。临床诊断为流行性脑脊髓膜炎。对于该患儿最重要的抢救措施为()
A. 降温
B. 抗休克
C. 抗感染
D. 降颅内压
E. 镇静
F. 止血
男性,12岁。患髋关节结核,未坚持正规的抗结核治疗。病初为间歇性关节疼痛,后突然出现剧烈持续性关节痛,难以步行,此时最可能是()。
A. 并发化脓性关节炎
B. 股骨颈骨折
C. 全关节结核
D. 股骨头坏死
E. 髋关节滑膜嵌顿