Ellise Shafer administratorMarvel’s “Black Widow” is poised to make an $87.8 million debut at the domestic box office, which would best the pandemic-era opening record previously held by “F9.”Having raked in a mighty $39.5 million on Friday from 4,160 theaters, “Black Widow” is set to easily earn another $48 million on Saturday and Sunday, with a final number that may shoot even higher than industry estimates.