Select all sentences that use the future continuous or future perfect correctly.
The builders promise the stage will be ready by 9 a.m. on Monday; at 9 a.m. they will be assembling it.
At 3 p.m. tomorrow, the swimmers will be crossing the lake halfway through their race.✓Correct answer
Guests arrive throughout the reception from seven until ten; at eight, the hosts will have welcomed every guest.
By 31 December, the volunteers will have scanned all 8,000 archive cards.✓Correct answer
Explanation
The swimmers will be mid-race at the stated moment, and the archive target is a completed total by a deadline. The stage sentence wrongly uses a progress form despite guaranteed completion, while the reception sentence wrongly uses a completion form for an activity known to be underway then.