| 61. | Portable boiling elements that can boil small quantities of water are useful when the right voltage of electricity is available. |
| 如果有相配的电压，可以煮少量水的便携式热水装置是有用的。
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| 62. | It may also be said that rational, industrious, useful human being are divided into two classes: first, one. |
| 也可以这样说，理智的，勤劳的、有用的人可以分为两类：第一类是他分清工作是工作，娱乐是娱乐的人；第二类人的工作和娱乐是一回事。
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| 63. | It is useful to partition a graph into its components. |
| 把一个图分解成它的分支，是很有益的。
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| 64. | Many parents believe that additional educational activities enjoy obvious advantage. By extra studies, they maintain, their children are able to obtain many kinds of practical skills and useful knowledge, which will put them in a beneficial position in the future job markets when they grow up. |
| 许多家长相信额外的教育活动有许多优点，通过学习，他们的孩子可以获得很多实践技能和有用的知识，当他们长大后，这些对他们就业是大有好处的。
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| 65. | Although many people tend to live under the illusion that traditional technology and methods are still playing extremely important role in people's life, an increasing evidences show that it is less useful than many people think. |
| 尽管许多人保持着传统观念，认为传统技术方法在人们生活中仍发挥着重要作用，但是越来越多的证据显示它并没有人们想象的有用。
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| 66. | But is it really the case? The information I've collected over last few years leads me to believe that artistic and cultural projects may be less useful than many governments think. In fact, basic infrastructure projects are playing extremely important role and should be given priority. |
| 这是真的吗？这些年我收集的信息让我相信这些文化、艺术项目并没有许多政府想象的那么重要。事实上，基础设施建设非常重要，应该放在首位。
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| 67. | Now, however, thechnology has advanced to the point where the useful mobile robot is an immediate possibility. |
| 然而现在，技术已发展到能立即制造实用又能行走的机器人的阶段。
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| 68. | People differ in their attitudes towards failure. Faced with it, some of them can stand up to it, draw useful lessons from it and try hard to fulfill what they are determined to do. Others, however, lose heart and give in. |
| 人们对失败持有不同的态度。面对失败，有人能够经得起考验，从失败中汲取教训，并努力去完成他们下定决心要做的事情。然而，另一些人却丧失信心并退却了。
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| 69. | The information I've collected over last few years leads me to believe that this knowledge may be less useful than most people think. |
| 从这几年我搜集的信息来看，这些知识并没有人们想象的那么有用。
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| 70. | To him I owe the discovery that even very short periods of time add up to all useful hours I need, if I plunge in without delay. (Johm Erskine, American educator) |
| 感激他使我 发现即使是很短的时刻，只要我分秒必争的一头钻进工作，积累起来就成为我需要的特别有用的几个钟头。(美国教育家 厄斯金.J.)
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