As a kind of commodity, petroleumprice fluctuates according to the law of supply and demand.
石油是一种商品，其价格的波动遵循供需规律。
2
Qatar has been one of the highest income countries in the world with the export income increased sharply in light of climbing international petroleumprice.
随着国际油价的节节攀升，卡塔尔出口收入急剧增加，已使其成为世界上人均收入最高的国家之一。
3
Based on the WTI price data between the end of 2002 and the beginning of 2006, an ARIMA model is built to make a forecast of the tendency of petroleumprice.