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问题 不定项选择

通常情况下，列车所受阻力与车速的平方成正比，即f=kv2。如果相同的两列车分别以v1=120 km/h和v2=40 km/h的速度匀速行驶，两机车功率大小之比P1：P2等于 [ ]

A. 3:1

B. 9:1

C. 27:1

D. 81:1

答案

答案：C

填空题

根据首字母或所给中文提示，写出正确的单词完成句子。

1. The headmaster excitedly a____________ the school sports meeting began.

2. Obama is a good speech maker and his first speech as president made a strong i_________ on his

    audience.

3. The farmers in this area had a good harvest last year thanks to the s________ farming.

4. His friends were ___________________(热情)and encouraged him to publish his ideas.

5. Berlin sounds fascinating from your ____________________(描述).
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单项选择题 案例分析题

男性，65岁，高血压病史20年，慢性心房颤动病史2年。长期口服普罗帕酮（心律平）、地高辛治疗。

患者因头晕、胸闷、憋气就诊，听诊发现心音规则，心率40次／分。最可能是下列哪种情况（）

A.恢复窦性心律

B.转变为房性心动过速

C.转变为房扑（房室传导比例固定）

D.发生室性心动过速

E.房颤伴第三度房室传导阻滞
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