(B) persistent...irritated
He set a giant boulder at the mouth of the cave.
- Flashcards
- Immerse Yourself.
- Study Words in Context
- See a Word, Speak a Word
- Use Visual Cues
- Play Games and Use Language Apps
- Make Good Use of the Dictionary
- Learn Word Parts
It's got to be C because none of the others relate to collaboration, but I'd say if you were unsure about this answer then the only other sensible one could be B, but I'd go with C.
