Привет! Давай разберем, как раскрыть скобки для каждого предложения. Тут речь идет об использовании Future Perfect Continuous. Сначала давай вспомним, как образуется эта форма: Subject + will have been + глагол с окончанием -ing.
Теперь проработаем предложения шаг за шагом:
My uncle (to live) – "My uncle will have been living in this city for 5 years by next summer."
Sam (to watch) – "Sam will have been watching the series for 2 months by October."
Tom (to repair) – "Tom will have been repairing his room for half a year by December."
They (to hold) – "They will have been holding the day for Jhon for 10 years."
By the end of the year you (to be) – "By the end of the year you will have been being here for 5 months."
By the end of the day my granny (to cook) – "By the end of the day my granny will have been cooking for 7 hours."
By the end of this year he (to study) – "By the end of this year he will have been studying English for 3 years."
Если что-то непонятно, спрашивай! Мы разберем вместе.