摘要： U.S. oil drillers have made major efficiency improvements with a speed that has repeatedly surprised analysts.美国石油钻井工的效率得到了极大的提高，现在的钻井速度不断让分析师感到惊讶。 I' 阅读全文

摘要： 31w/m 51error It is a good thing my aunt Harriet died years ago. If she were alive today she would not be able to air her views on her favourite topic 阅读全文