Read the grumpy cat's inner monologue. Select ALL the sentences that correctly apply the Future Perfect Continuous to express his dramatic suffering.
The correct answers are If she doesn't feed me by 6 PM, I will have been waiting by my bowl for three excruciating hours. and By the time she finally opens the tuna, I am going to have been meowing continuously since noon.
Both will have been + verb-ing and be going to have been + verb-ing are valid ways to form the Future Perfect Continuous tense!
"Will have been waited" is incorrect because it uses the past participle instead of the present participle (-ing).
"Will have been starved" is the Future Perfect in the passive voice, not the Future Perfect Continuous.