According to the different casing, the welding groove of all parts is classified and the form of welding groove and the welds marking number used commonly in casing are determined.

针对不同形式的机壳，进行各部位焊接坡口形式分类，确定机壳中常用的焊接坡口形式、焊缝标注代号，为设计者在焊接机壳的设计中提供了方便和依据。

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When the gun is fired the marking theoretically leaves a serial number on the primer encased in the spent cartridge.

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Key Stage 2 test markers, who are practising or retired teachers, receive thorough training and undergo a number of quality checks through the marking process.

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It has promised longer sentences for people who carry guns illegally and new electronic marking of state-owned weapons in the hope of cutting the number of Kalashnikovs seeping into the black market, where they are bought more cheaply than anywhere else in the world.

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