Answer:
In Gerund form. (+ing).
Explanation:
This occurs since the tenses must be structured like this:
FUTURE PROGRESSIVE:
I will be ______________(VERB in gerund) +ing by tomorrow.
PRESENT PERFECT PROGRESSIVE:
I have been ____________(VERB in gerund) +ing all day.
FUTURE PERFECT PROGRESSIVE:
I will have been___________(VERB in gerund) + ing tomorrow by noon.
C. Holmes lets him go free, because there wasn't enough of a case.
