中国大学MOOC: Five thousand dollars ________ quite a large sum for him.
                    举一反三
- Five thousand dollars _____ quite a large sum for him. A: are B: were C: is
 - Five thousand dollars _________ large sum for him.
 - Five thousand dollars large sum for him. A: are B: is C: were D: have
 - Ten thousand dollars _____quite a large sum.
 - Twenty thousand dollars ____ quite a large sum. A: is B: are C: were D: has
 
