expanding gas短语¹⁴⁴⁹⁷²⁺² 基本例句 🌏膨胀气 When the well reaches a pool, oil usually rises up the well because of its density difference with water beneath it or because of the pressure of expanding gas trapped above it. 当钻井抵达油池，油通常会由于密度与水不一样和浮到水面上或者由于压在底层的压力让他们浮上来。 xiaoma