小纸片会在发声的扬声器的纸盒上跳动,发声的音叉接触水面时会激起水花,风吹树叶哗哗响,树叶在振动.这些现象说明了( ) A . 声音是由物体振动产生的 B . 声音能在水中传播 C . 声音的传播需要介质 D . 声音能在空气中传播 答案:A—Is the girl is interviewing the manager of that company your friend? —Yes, she is a journalist from CCTV.
[ ]A. whom B. which C. who D. whose