shale tar

例句：

1. 1. The shale oil extraction process is complex and requires a lot of investment.
   页岩油提取过程复杂，需要大量投资。
2. 2. The shale gas industry is expected to grow rapidly in the coming years.
   预计在未来几年内，页岩气行业将快速增长。
3. 3. Shale gas has become an important source of energy for many countries.
   页岩气已成为许多国家的重要能源来源。