Some day I happened to find a chatting room in my QQ, there people were chatting in English. I tried to chat with some of them. To my surprised, I found the oral English of some junior students were better than me. I asked them for advice and they told me to practise more on QQ. But every day after that I would spend one hour practise my oral English on QQ. Day by day I learned from many useful words and expressions. With time went by, I found that I could even communicate some college students freely.

某企业决定凭借产品的环保特点进入国际市场，它应采用( )系列标准。

A．ISO9001

B．ISO10011

C．ISO14000

D．ISO9004