流感血凝抑制试验鉴定结果判定的标准有哪些？

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问题问答题简答题

答案

参考答案：

（1）标准参照血清对待检抗原的抑制效价≥20才可以算为阳性。

（2）一种待检抗原不能同时被两种或两种以上的标准血清抑制。

（3）待检抗原标准参照血清有交叉抑制，但与一种亚型（B型流感称为系）的标准参照血清抑制效价大于其他亚型参照血清4倍以上时，便可以判定为此种亚型的流感病毒。

阅读理解与欣赏

阅读下面一首五言律诗，完成后面各题。

晨登衡岳祝融峰^{[注]
[清]谭嗣同
身高殊不觉，四顾乃无峰。
但有浮云度，时时一荡胸。
地沉星尽没，天跃日初熔。
半勺洞庭水，秋寒欲起龙。}

　　【注】祝融峰，南岳衡山的主峰，七十二峰的最高峰。光绪二十一年秋天，年仅26岁的谭嗣同登上此峰，写下了这首恢宏阔大的诗篇。

这首诗抒发了诗人怎样的思想感情？请结合首联或尾联加以分析。

答：____________________________________________________

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单项选择题

Believe it or not，optical illusion can cut highway crashes.
Japan is a case in point．It has reduced automobile crashes on some roads by Rearly 75 percent using a simple optical illusion．Butst．ripes,called chevrons(人字形)，painted on ther rads make drivers think that they are driving faster than they really are，and thus drivers slow down.
Now the American Automobile Association Foundation for Traffic Safety in Washington D．C. is planning t。repeat Japan’s success．Starting next year，the foundati。n will paint cheyrons and。ther pattems of stripes on selected roads around the country to test how well the patterns reduce highway erashes．
Excessive(too great)speed plays a major role in as much as one fifth of all fatal traffic accidents， according to the foundation．To help reduce those accidents，the foundation will conduct its tests in areas where speed-related hazards(danger)are the greatest curves，exit slopes，traffic circles，and bridges．
Some studies suggest that straight，horizontal bars painted across roads can initially cut the average speed of drivers in half．However,traffic。ften returns to full speed within months as driVers become used to seeing the painted bars．
Chevrons，scientists say，not only give drivers the impression that they are driving faster than they reallv are but als0 make a lane appear to be narrower．The result is a longer lasting reduction in highway speed and the number of traffic accidents．

What does the author say about straight,horizontal bars painted across roads

A. They are suitable only on broad roads.
B. They are falling out of use in the United States.
C. They are ignored in a long period of time.
D. They cannot be used successfully to traffic circles.

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