The valve stem and sealing surfaces are completely protected from dirt and corrosion by the stem cap, whether the valve is in an open or closed position.

不管是在阀门开启位置，还是关闭位置，阀杆和密封面有阀杆盖帽的保护，能防止污物入内，防止腐蚀。

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It is a special kind of stem cells with highly proliferative and self-regenerative cap ability to maintain its number stable and generate tumor.

肿瘤干细胞是一种特殊类型的干细胞，具备高度增殖能力与自我更新能力，其结果是维持肿瘤干细胞数目稳定并产生肿瘤。

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It is composed of a taper shank cap, a hollow taper shank, an awl perch, an awl stem casing, a permanent magnet and screwdriver heads of different format dimensions.

该改锥是由锥柄盖、空心锥柄、锥杆、锥杆套、永久磁铁和多个不同规格尺寸的改锥头组成。

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In an effort to stem capital flight, which has been rampant in France, the government plans to cap income taxes at 50%, from more than 60% now.

FORBES: Vive la Difference