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问题 单项选择题

6岁女孩，反复发生支气管肺炎，于2岁时体检发现胸骨左缘第2肋间有Ⅰ～Ⅲ级收缩期杂音，经进一步检查诊断为先天性心脏病：房间隔缺损。

在此病例未发生肺动脉高压前，其房间隔缺损的血流动力学改变是

A．增加了有心室和肺循环的负荷

B．增加了肺循环和左心室负荷

C．增加了肺循环右心室和左心室负荷

D．增加了右心室和左心室负荷

E．增加了右心室负荷

答案

参考答案：A

选择题

下列词语中错别字最多的一项是：

A．黯淡艳羡必恭必敬晃然大悟

B．惬意悭吝鞠躬尽粹仗义直言

C．誊写亲怩不知所错英雄倍出

D．笑靥纸绽冠冕堂皇莫明其妙
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单项选择题

A typical application of this (71) is ADSL. It is emerging as the technology for home-and small-office Internet connectivity. It provides either 1.5 Mb/s～8 Mb/s from the network to the user and 64 Kb/s～512 Kb/s in the reverse direction depending on the distance, 12 000 or 18 000 feet.. The different speed for each direction gives it the (72) label. ADSL is designed to take advantage of the fact that video-on demand, telecommuting, and Internet access traffic are inherently asymmetrical. The user (73) a brief message up to the network and receives a ton of data coming back, either a movie or a piece of data download. Under such a scenario, low-speed traffic to the network is just fine. ADSL delivers high (74) where you need it and only uses a single copper pair. Through multiplexing, it also reserves (75) of the bandwidth for POTS.

A．FTTH

B．HFC

C．FTTC

D．HDSL
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