What is the correct form of the modal structure in the following sentence? "Feed supplements _______ (ought / develop / test) on livestock at scale long before 2021."

Question

Answer

ought to have developed and tested

Answer

ought to had been developed and tested

Answer

ought to have been developed and tested

Answer

ought have been developed and tested

Crowdly

What is the correct form of the modal structure in the following sentence? "Feed...

Хочете миттєвий доступ до всіх перевірених відповідей на vo.uu.edu.ua?