来自丁艳军的问题
关于名词set"Asetofboxesisarrived."和"Asetofboxesarearrived"哪个对?"Twosetofboxesarearrived."和"Twosetsofboxesarearrived"哪个对?
关于名词set
"Asetofboxesisarrived."和"Asetofboxesarearrived"哪个对?
"Twosetofboxesarearrived."和"Twosetsofboxesarearrived"哪个对?

