It has slashed the cost of toll roads to almost one-tenth of the normallevel, attracting yet more people on to fume-choked roads.
它将收费公路的成本削减至正常水平的近十分之一，然而致使更多的人走上烟雾弥漫的道路。
2
Volunteers were told to think about yawning while they breathed either normal air, pure oxygen, or an air mixture with an above-normallevel of carbon dioxide.
Volunteers were told to think about yawning, while they breathed either normal air, pure oxygen, or an air mixture with an above-normallevel of carbon dioxide.