trial run       
noun [ C ] uk/ˌtraɪəl ˈrʌn/ us/ˌtraɪəl ˈrʌn/
 试行;试验;试用
a practical test of something new or unknown to discover its effectiveness
  We're holding a tournament in the new ice-hockey stadium, as a trial run for next year's Winter Olympics. 我们将在新的冰球场承办一次锦标赛,作为明年举办冬奥会的一次测试。 
 Synonyms: dummy run test 
Compare: try-out 
See also: trial noun