Question

complete the sentence with the present perfect form of the verb. since 1942, patriotic baseball fans in stadiums across the country \the star-spangled banner\ before the start of the game. sing

Explanation:

The present perfect tense is used to show an action that started in the past and continues to the present. The structure is "have/has + past participle". The subject "patriotic baseball fans" is plural, so we use "have". The past participle of "sing" is "sung".

Answer:

have sung