难得

It's also found in cod liver oil, but that's a rare menu item.

它的还发现，鱼肝油，但这是一个难得的菜单项目。

When he sits alone at a scarce moment, silhouette of the coir raincoat turns up clearly, staying adamantly at one corner of his mind.

当他在难得的寂静时分一个人端坐，蓑衣的影子就清晰地显现出来了，在脑海的某个角落里难以拂去。

It is important for the cooling rate and quality of foodstuffs in the cold store with the uniform flow and temperature field.

合理的气体流场才能保证均匀的温度场，这对冷藏库内货物的降温速率和贮藏质量起着至关重要的作用，而常规设计方法很难得到合理的气体流场。

It may be a rare collectable or it may be a long forgotten motorcycle part that is hidden in the back of the shed.

它可能是一个难得的收藏，也可以是一个长期被遗忘的部分就是隐藏在摩托车背面的大棚。

I know it is a rare one and very collectible, but I need to know more.

我知道这是一个非常难得的收藏品，但我需要知道更多。

Actually, this also is collective of domestic SP enterprise turns model the Gao Chao with one god-given Ge.

实际上，这也是国内SP企业集体转型的一个难得的高潮。

As the coloratura mezzo-soprano singers, it is difficult for them to perform the coloratura skill due to its modernity, its overwhelming presentation and its comprehensive and extraordinary development.

花腔作为美声唱法传统技能技巧具有一定的美学原则和艺术思想，女中音能够演唱花腔技术是很难得，她不仅是美声唱法的追求和特点，更是女中音声部想要全能全面发挥所要具备的歌唱技能技巧。

From the view of mathematics, it is a NP-hard combinational optimization problem with constraints and it is difficult to find the global optimal solution in theory.

从数学上讲，机组投入问题是一个多约束的NP-hard组合优化问题，很难得到理论上的最优解。

Friends are hard to come by..

朋友是很难得的。。。

This is a chance hard to come by.

这是难得的机会。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。