诚然，从诸如加拿大油砂油等替代石油供应持续增长，但是无论从货币上还是从环保上讲，这种替代来源的相对成本都太高。

True, alternative sources, like oil from Canada’s tar sands, have continued to grow. But these alternative sources come at relatively high cost, both monetary and environmental.

youdao

诚然，从诸如加拿大油砂油等替代石油供应持续增长，但是无论从货币上还是从环保上讲，这种替代来源的相对成本都太高。

True, alternative sources, like oil from Canada's tar sands, have continued to grow. But these alternative sources come at relatively high cost, both monetary and environmental.

youdao

三是成品油供应压力加大。

Pressure is mounting on the supply of oil products.

youdao