Attaching radio devices to it is difficult, and visual sightings are too unreliable to give real insight into its behavior.
给它安装无线电设备是很困难的，而且仅凭肉眼观测也太不可靠，无法对它的行为进行确切的观察。
These methods may be useful for a while, but it is difficult to solve this problem completely.
这些方法可能暂时有用，但要完全解决这个问题是很困难的。
With so many variables, it is difficult to calculate the cost.
有这么多的可变因素，很难计算出成本。
When a city's population grows by 5% a year, it is difficult to keep up.
当一个城市的人口以每年5%的速度增长时，基础设施很难跟得上。
You won't know what he means at first, for it is difficult to understand him.
起初你不知道他是什么意思，因为很难理解他。
With such a long interval, it is difficult to determine the age of this fossil.
时间隔得这么久了，很难确定这化石的年代。
Some people believe that it is difficult to protect users' privacy on social network sites.
一些人认为很难在社交网站上保护用户的隐私。
Crowding on Mooreville's subway frequently leads to delays, because it is difficult for passengers to exit from the trains.
穆尔维尔的地铁拥挤不堪，经常导致晚点，因为乘客很难从火车上出来。
Targland's officials predict that these measures will be adequate, since it is difficult to collect the tortoises without a vehicle.
塔格兰德的官员预测这些措施将是足够的，因为没有交通工具的话，很难收集这些乌龟。
It is also true that it is difficult to think of a single such system that has not, for better or worse, been substantially modified by human culture.
同样，很难想象一个这样的系统：不管是好是坏，都没有经过人类文化的实质性修改。
In large cities, people complain it is difficult to breathe.
在大城市，人们抱怨呼吸困难。
These days it is difficult to imagine a world without books.
如今，很难想象一个没有书的世界。
For the students in one small village in China, it is difficult.
对于中国一个小村庄的学生来说，这很困难。
We will manage to accomplish the task in time even though it is difficult.
纵然任务艰巨，我们也要及时完成。
If that is not culture, it is difficult to think what is.
如果这不是文化的话，那么很难说这到底是什么。
It also explains why it is difficult to get rid of a bad habit.
这也解释了为什么很难改掉一个坏习惯。
Just know, that it is enough sometimes to know that it is difficult.
有时候知道难就够了。
But it is difficult to get into the industry, and harder to stay there.
然而，目前，进入此行业有一定的难度，想要立足于其中更是难上加难。
But it is difficult to say if these reactions are instinctive or learnt.
但想要分清这些反应是先天本能，还是后天习得可不是那么容易。
The custom began so long ago, it is difficult to know how it got started.
这项风俗由于起源很早，所以很难知道它最初是怎样开始的。
Just as with public goods, it is difficult to prevent people from using the Commons.
就像公共物品的情况那样，要想防止人们使用共同资源是很困难的。
If we see a person first in a good light, it is difficult subsequently to darken that light.
如果我们对一个人的第一印象很好的话，想要把这个印象变坏也是很难的。
Because you are very kind-hearted, it is difficult to form words, I wish you a Happy Father's Day!
因为您慈祥无比，难以言表，祝您父亲节快乐！
Jump hook: a hook shot taken while jumping, popular among big men because it is difficult to block.
勾手跳投(jump hook)：起跳时的勾手投球，因为很难防守，所以在个子高的球员中特别流行。
He admits it is difficult to make accurate comparisons, because the research is still in its infancy.
他承认很难作出精确的比较，因为这项研究仍处于初级阶段。
For beginners, ordinary people like us, it is difficult to understand the true practice of love and compassion.
对于一个初学者，一个像我们这样的普通人，往往很难理解爱与慈悲的修持真谛。
Reasoning is also developed early on, although sometimes it is difficult to explain reasoning to a two-year old.
推理的能力在小时候也得以培养起来，尽管有时候向一个2岁的小孩解释推理甚为困难。
Most of our relationships, in fact, require more time than we have, and it is difficult to avoid the feeling that we could never have enough.
大多数人际关系实际上都需要更多的时间去维系，因此难免总感觉时间不够用。
Under those circumstances, it is difficult to see how the world economy can return to the pre-crisis levels of growth, or even close to them.
在这种情况下，很难想象全球经济如何能恢复到危机前的增长水平(甚至接近这一水平)。
Under those circumstances, it is difficult to see how the world economy can return to the pre-crisis levels of growth, or even close to them.
在这种情况下，很难想象全球经济如何能恢复到危机前的增长水平(甚至接近这一水平)。
应用推荐