四倍

Air pollution in the city had reached four times the acceptable levels.

这座城市空气污染程度曾高达可接受标倍。

Our profits have quadrupled in ten years.

10 年里我们利润翻了两番（即增至倍）。

Prices quadrupled in ten years.

十年内价格增至原来倍。

Each frame is scrubbed four times to erase jaggies, and PGR3 still runs at 60 frames per second - twice the rate of TV.

就是PGR3在倍全屏抗锯齿下面一流，而且还是以60帧/秒速度运行。

"Some of the well-known types are the durum, emmet , Polish, and poulard. These are tetraploids. and there is the einkorn, which is a diploid. "

有些类型是大家都很熟悉，比如硬粒小、二粒小、波兰小、小。它们都是倍体。此外还有一粒小，是二倍体。