Fill in the blank with the most appropriate word.
The two children ____ to look forward ____ to their grandparents house at Christmas
The
verb or verbs in a sentence should complement the tense of the sentence. In
this question, option B is correct as “used” in simple past tense does not
require an adverb of time and the verb “going to” concurs with the past
continuous tense which indicates persistent habits, as given in the context. Thus,
option B is the correct answer.
“Use” in option A is grammatically incorrect as the tense of this verb does not
concur with the rest of the sentence.
Both options C and D are incorrect as “used to” cannot be used with a third “to”
as would happen if these options are used.
Thus, option B is the correct answer.