难得

Rheumatic fever, once the most common cause of joint problems in children, and the commonest cause of heart-valve disorders, is now fortunately rare in the developed world.

风湿热，一旦最常见的原因联合的问题，在儿童，最常见的原因，心脏瓣膜疾病，所幸的是现在难得在发达世界。

It's far better to own a significant portion of the Hope diamond than 100% of a rhinestone, and the companies just mentioned easily qualify as rare gems. Best of all, we aren't limited to simply a few of this breed, but instead possess a growing collection.

我们宁愿拥有天然钻石的一小部份，也不要有100%的人工钻石，而刚刚提到的那些公司堪称为天然的稀有宝石，更难得的是我们不是只拥有现在这一些，以后还会得到更多更多。

An effective and simple method for total RNA extraction from rhizobium was described in this paper. The method had the acquirement of high RNA yields and was less expensive than other methods previously described.

0前言提取高纯度、完整的总RNA是对基因进行转录水平操作的基础，但不同生物往往因种属差异、材料内含物组份及含量的差异，而需要采用不同的RNA提取方法，对细胞组成成分复杂的生物物种，RNA的提取相对困难得多。

Rickets is now rare in developed countries.

佝偻病是现在难得的是在发达国家。

And, as every HR Manager knows, it is much more difficult to get rid of someone than it is to employ them.

人力资源经理都知道，辞去一名员工比招聘一名员工要困难得多。

Astronomy the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day.

从天顶交叉口向西顺着天赤道测量的一个角距离；对在一个特定的地点和特定的时间观测者来说是赤经。机会难得！足额稳定绿色激光笔团购！

It was a rare --- indeed unique --- occasion when I was able to put Ritchie right.

这是一个难得的---确实是独一无二的时机---使我能够纠正里奇的断言。

Without doubt, the heating power is one of these two seasons Milanbiggest luminescent spots in heating power this age, can have hissituation, when specially downcasts between the multitudinous match,he in front of toe roquet, always can want good to make any first.Says from this angle, the vanguards all very are willing with the

无疑，卡卡是这两个赛季米兰最大的亮点之一在卡卡这个年龄，能有他的技术确实非常难得在空间并不是很大的情况下，特别是陷落于众多对手之间时，他在脚趾碰球之前，总能先想好做什么。

With less than a dozen female players participating in the 2005 WSOP, professional female poker players are still as rare as a royal flush.

少于十女选手参加2005年的讲习班、职业女球员朴仍难得作为皇家搜捕。

It is a rare opportunity to rub shoulders with the rich and famous.

这是个与富翁名人来往的难得机会。

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。