In Chicago's Millennium Park, the Crown Fountain displays images of locals on a glass block tower.
芝加哥城市生活图片。在芝加哥的千禧年公园，王冠喷泉显示图像当地人在一块玻璃塔上。
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The drilling line is reeled over the crownblock and traveling block to gain mechanical advantage in a "block and tackle" or "pulley" fashion.
钻井用钢丝绳通过天车和游动滑车以滑轮组的形式获得机械上效益。
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Conclusions Applying 30% supersaturated potassium oxalate to block dentinal tubule could prevent or reduce crown surface discoloration effectively after front teeth canal therapy.