电压表只要量程允许是可直接接在电源两端的，这是因为电压表的电阻很 ______，由欧姆定律可知，通过电压表的电流很小，不会烧坏电压表．因此在分析电路时可以把电压表看作是 ______的一段电路．

Chemical processes _______in the treatment of materials for clothes _______the environment badly in some countries nowadays．

A．involve；damaging

B．involved；damaged

C．involving；damage

D．involved；damage