【单选题】Yesterday, the couple went downtown and bought ______ .
B.
two pieces of furnitures
D.
two pieces of furniture
【单选题】电动机虽然种类繁多,但基本结构均由( )和转子两大部分组成。
【单选题】About ______ students went to the show yesterday.
【单选题】He went there as a volunteer on a ________ program.