It is, therefore, essential that a banksman be appointed to warn the operator of hazards that cannot be seen from the operator's position.

重型运土设备使用时，操作人员只能看到有限的区域，因此，必须指派矿口监工随时警告操作人员在操作位置上无法发现的危险。

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The stars are beautiful, because of a flower that cannot be seen.

星星是很美的，因为有一朵看不见的花儿。

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A device to find objects that cannot be seen called Radio Detecting and Ranging became Radar.

“装置找到对象，不能被所谓的无线电探测和测距，成为”雷达。

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Investigators sometimes use chemicals and special lighting to uncover fingerprints that cannot be seen with the eye alone.

VOA: special.2010.05.05

Anderson pathologist Mary Elizabeth Edgerton are creating a simulation that predicts the location of cancer deposits that cannot be seen on mammography.

FORBES: Can Math Cure Cancer?

Next imagine groups of malicious vandals that cannot be seen .

FORBES: Crimes No One Can Stop -- Attackers No One Can Find

Physics may tell us that photography should simply be a record of what can be seen, yet these artists show that it can be so much more when in the right hands, often revealing that which cannot be seen.

BBC: Documentary photography on show