[ Adjective + to + Verb ]
it’s difficult to understand
A. a dog
B. a plane
C. an English book

Random Topics:
Relative Clauses beginning with PrepositionsPast Tense and Perfect Tense1st and 2nd ConditionalsConjunctions and Verb TensesModal Verbs for Permission and ObligationConjunctions in Complex Sentencesa, an, the, zero articleAdverb Clause ConnectorPossessive PronounsGerunds and InfitinitivesOther quiz:
Prepositions › ViewWhich sentence contains a collective noun?
A. The hospital staff held a meeting.
B. The doctors discussed their schedules.
C. One nurse voiced a complaint.
If Conditional › View
If you get a haircut, you _______ much better.
A. look
B. will look
Tenses › ViewLook out! We __________ crash!
A. are going to
B. will
C. shall
Grammar › View
a premise that is untrue or distorted
A. premise
B. false premise
C. faulty reasoning
D. false consensus