Used to control access to nuclear weapons, retina identification has never caught on with the public because it requires the users to put their eyeball right up against a lens.

网膜辨识比较的是眼睛后方血管的模式，曾被用来管制核武器的操控权，但是它始终未能广泛应用，因为使用者得把眼球凑到透镜上。

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With the successive budget cuts eviscerating our conventional forces, it is not clear how much of a fight the military leadership will put up to preserve weapons that may be the ultimate guarantor of our security but that some deem unusable.

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The U.S. and Afghan commando teams put on heavy armored vests, helmets and ballistic eyeglasses and pick up their American-made weapons.

NPR: U.S.-Afghan Force Raids Suspected Taliban Hideout

Military prosecutors say West followed up on that threat by taking the suspect outside, put him on the ground near a weapons clearing barrel and fired his 9 mm pistol into the barrel.

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