the fifth column

基本解释

The fifth column contains the user's full name, or a comment.
第五列是用户的全名，或者是注释。
Beware of the fifth column. They often infiltrate into key positions and seek to undermine the body politic from within.
要提防隐蔽的敌人，他们经常渗透到关键岗位企图从内部破坏国家政体。
The fourth column shows the improvement introduced by the MQTs as a time difference between the second and third columns and the fifth column shows the percentage of the improvement.
第四列展示 MQT 引入的改善，即第二列和第三列之间的时间差异，第五列展示改善的百分比。

The trip to Spain resulted in two works, a play called "The Fifth Column" and the novel "For Whom the Bell Tolls."

He would soon complete The Fifth Column and the First Forty-Nine Short Stories (1938) and start work on For Whom the Bell Tolls (1940).
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Incredible as it may seem, the apparent absence of any laws on the books that would make it a crime simply to organize essentially a Libyan Fifth Column for the purposes of accomplishing America's violent dismembering may mean that -- like Al Capone -- Louis Farrakhan could only be prosecuted for more prosaic violations.
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Indeed, even before any new influx of Arabs into Israel occurs, the Jewish State is increasingly facing a "time bomb" of its own -- an armed and dangerous Palestinian nation emerging in its midst and the prospect of a fifth column formed from Arab citizens of Israel.
CENTERFORSECURITYPOLICY: Israel's Ticking 'Time Bomb'