Sent_en: 2zh Statoil admits, however, that heavy oil production, such as is required in the oil sands, is "energy intensive and challenging in an environmental perspective."
Sent_yy: 然而，挪威国家石油公司承认，重油生产，如油砂开采所需要的重油，是“能源密集型的，从环境角度来看具有挑战性”。