dry run

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++ˌdry ˈrun noun [countable]  PRACTISE/PRACTICEan event that is a practice for a more important event 演习，排练 Both the parties are treating the local elections as a dry run. 两党都把地方上的选举当成一种预演。

Examples from the Corpus

dry run• BIn some ways, the learning center provides a dry run for the workaday world.• Apprenticeships enable companies to screen future workers and give them a dry run before selecting the best for long-term employment.• They were there for a countdown dry run.

ˌdry ˈrun nounChineseSyllable  

an a Corpus event is practice for that

dry run
ˌdry ˈrun noun [countable]
an event that is a practice for a more important event:
    Both the parties are treating the local elections as a dry run.

dry runBrE /ˌdraɪ ˈrʌn/ 🔊NAmE /ˌdraɪ ˈrʌn/ 🔊 noun [usually singular] a complete practice of a performance or way of doing sth, before the real one 排练；演习 SYN dummy run