难以

The performance of magnetic levitation is determined mainly by the characteristic of its controller and solving the problems of the high precision, high esponse frequency, output immune from the disturbance, the parameter perturbation and the uncertain factors from outside is very difficult. The traditional methods can not meet the needs of the system. So it has great significance to study the control method of magnetic levitation.

磁悬浮系统性能的优劣很大程度上取决于控制器的特性，高精度、高响应频率和输出不受外界干扰的特性以及磁悬浮中参数的摄动和外界不确定的干扰因素都是难以解决的棘手问题，传统控制难以满足系统要求，因此对控制方法的研究有其非常重要的意义。

The performance of magnetic levitation is determined mainly by the characteristic of its controller and solving the problems of the high precision, high response frequency, output immune from the disturbance, the parameter perturbation and the uncertain factors from outside is very difficult. The traditional methods can not meet the needs of the system. So it has great significance to study the control method of magnetic levitation.

磁悬浮系统性能的优劣很大程度上取决于控制器的特性，高精度、高响应频率和输出不受外界干扰的特性以及磁悬浮中参数的摄动和外界不确定的干扰因素都是难以解决的棘手问题，传统控制难以满足系统要求，因此对控制方法的研究有其非常重要的意义。

Phantasmagoria are not mere figments of our imagination, they also serve to shape the incomprehensible and the elusive and make it manageable.

幻影不仅是我们想象中的虚构事物，它也有助于表现难以理解和难以实现的事物，并使之易于驾驭。

This was a hard requirement to make or to procure.

这是一个难以出口，也难以办到的要求。

Especially, in some cases, where the required conditions that the connecting-line of the two pupils parallel to the reference plane and the projecting and imaging axes must be horizontal can not be met, the new method offers a flexible way to obtain the reliable height distribution of a measured object.

本文所提出的方法为在难以实现双瞳与参考面平行或难以使双轴共面的特殊环境下的测量提供了获得可靠测量结果的途径，同时也为傅里叶变换轮廓术进入实用领域打下了坚实的基础。

I'll explain to you a sagacity hard to do, hard to endure.

世尊说道：我将为你讲述这难以达到、难以获得的智慧。

It's hard to look into the starry night and not succumb to hopelessness, because all our history is like the shadow of a bird on the ocean-a fleeting moment in the unimaginable.

心儿似乎难以穿越星光之夜，而不屈从于茫然与无望。我们的生命之旅不过如同海面上飞鸟的影子，倏然一晃便杳无踪迹，短暂须臾难以想象。

It's hard to took into the starry night and not succumb to hopelessness, because all our history is like the shadow of a bird on the ocean-a fleeting moment in the unimaginable.

心儿似乎难以穿越星光之夜，而不屈从于忙于无望。我们的生命之旅不过如同海面上飞鸟的影子，倏然一晃便杳无踪迹，短暂须臾难以想象。

It's hard to look into the starry night and not succumb to hopelessness, because all our history is like the shadow of a bird on the ocean – a

心儿似乎难以穿越星光之夜，而不会屈从于茫然与无望，我们生命之旅不过是海面上飞鸟的影子，倏然一晃便杳无踪迹，短暂须臾，难以想象。

However, the characteristics that the multiple constraints and sequences in the auto-body assembly make the error stack-up very complex and it is difficult to search dimension-loop by utilizing the traditional dimension loop model in the 3-D variation analysis and synthesis in auto-body. Meanwhile, for the auto-body composed by great mounts of parts, the traditional Monte Carlo Simulation is time-consuming.

然而，车身装配过程中零件间的多约束特征和多装配顺序影响，使得车身装配偏差累积规律十分复杂，传统尺寸链分析方法需要建立尺寸链方程，难以适应车身三维偏差分析；同时，传统的蒙特卡洛求解方法计算效率低下，难以应用于这种复杂车身产品的公差综合。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。