三价

If vaccinal measles vaccine can prevent hives, take a poliomyelitis tervalent mixture vaccine can prevent a poliomyelitis to wait.

如接种麻疹疫苗能预防麻疹，服脊髓灰价混合疫苗能预防小儿麻痹症等。

At present, trivalent chromium electroplating process has became one of the mostimportant techniques to taking place of the seriously pollutional hexvalent chromiumelectroplating process.

目前，价铬电镀工艺已经为取代重污染六价铬电镀的最重要技术之一。