opportunistic       
adjective uk/ˌɒp.ə.tʃuːˈnɪs.tɪk/ us/ˌɑː.pɚ.tuːˈnɪs.tɪk/
 usually disapproving投机的;机会主义的 
using a situation to get power or an advantage
  He made an opportunistic grab for power, which resulted in a civil war. 他抓住一个机会夺了权,导致了内战爆发。 
 At half-time, United were leading with two opportunistic goals by Black. 上半场结束时,联队因布莱克打进两个机会球而领先。 
 Synonym: opportunist 
 - More examples
 - Some crimes are opportunistic, often done at the urging of friends.
 - Opportunistic lawsuits and damning headlines do nothing to prevent medical errors.
 - Most people with AIDS die of opportunistic infections once they are immune compromised.
 - HIV is like any other opportunistic organism which develops in the body having low body immunity.