It is estimated that more than 50 million people in the United States play a musical _________

It is estimated that more than 50 million people in the United States play a musical __________.

It is estimated that more than 50 million people in the United States play a musical __________.
A、tool
B、 device
C、 appliance
D、 instrument
【正确答案】：D

企源知识库