该方法的缺点在于集光型太阳能收集器往往体积比较庞大且造价昂贵，以及太阳光泵浦激光正常情况下功率太低。
The trouble is that concentrated solar collectors tend to be huge and costly, and solar-pumped lasers are normally very low powered.
你需要一大票的导弹舰才能消灭一整群的防御建筑，如果使用和那些防御总合造价相同的战列来攻击会比较划算。
You need a great amount of them to kill a big defense, but it will come cheaper as if you had attacked that defense with battleships with the same costs.
介绍了管道塑膜内衬的施工工艺和内衬特点，经比较其施工工期短、造价低。
The article introduces construction process of the plastic film inner lining and its characteristics of short construction term and low cost by comparison.
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