In at-home treatments, patients wear a mouth guard fitted with bleaching gel 2 hours a day for two weeks, depending on the severity of staining.

而采用家庭治疗，患者只需连续两个星期每天戴上涂有漂白凝胶的护齿两个小时就可以了。具体治疗时间取决于牙齿被染色的严重程度。

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For the extended well, high angle drilling, horizontal drilling and deep well drilling, or in the well section of large dogleg severity, or the long open hole, casing wear often happens.

在大位移井、大斜度井、水平井和深井钻井中，或者在狗腿严重度较大的井段，或者在技术套管下入后的长裸眼钻井过程中，常常出现套管磨损问题。

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The problem of eccentric wear of tubing and rod strings in rod pumped Wells is very severity in recent years, and led to service frequently, pump inspection period shorten and service cost enhanced.

近年来抽油机井管、杆之间的偏磨问题十分突出，导致作业频繁，检泵周期短，作业成本增加。

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