电子标签通常是由（）组成。
A.标签表面
B.标签信号
C.标签天线
D.标签芯片
参考答案：C, D
My math teacher often goes to school _____. [ ]
A. by the bike
B. by his bike
C. by bike
D. on bike
如何培养班级积极向上的健康舆论？
