Mr. Li has ordered for the school lab.
A. three equipments
B. three pieces of equipments
C. three pieces of equipment
D. three pieces equipment
网友回答
A. three equipments
B. three pieces of equipments
(答案→)C. three pieces of equipment
D. three pieces equipment
解析：equipment为不可数名词，表示复数要在前面加上数量词。