如果有50%进行升级换代，将卖出四千八百万部。

If 50% upgrade, it will sell 48 million.

此外还要花费数十亿美元给现有的铁路升级换代。

Billions more will have to be spent on upgrading existing railroads.

我们马上丢弃旧的缝纫机或照相机，或者将他们或者升级换代，而不是修理他们。

Instead of fixing an old sewing machine or camera, we immediately toss it and upgrade.

数千辆公交车正在升级换代，以使用更为清洁的燃料，另外加油站也在进行改造以减少汽油挥发。

Thousands of buses are being upgraded to burn cleaner fuels, and fueling stations are being modified to release less fuel gasoline into the air.