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核心詞議：

速記方法


知識擴展


中文詞源： ppm
精選例句

常見考點例句：

Concentrations of 10 ppm can be endured for only a few minutes and cause profuse lacrimation in all people .

10ppm的濃度，只需幾分鐘，就會使所有的人流淚不止。

It has a repulsive acidic odor that can usually be detected at or below a concentration of 5 ppm .

它有一種另人厭惡的酸味，在濃度為5ppm或以下可以察覺到。

Type I Diabetes mellitus usually starts from adolescent , whose morbidity rate is about 83 ppm and still increases .

I型糖尿病主要累及青少年，患病率萬分之0.83，還在不斷增長。

By chance , oryza sativa is a like aluminum plant , its optimum concentration is 30 ppm was observed .

意外觀察到水稻是喜鋁植物，最適濃度是30ppm。