有形市场
参考答案:
有固定交易场所的市场。
如图所示,用尺子作乐器探究决定音调高低的因素,把钢尺紧按在桌面上,一端伸出桌边,拨动钢尺,听它振动发出的声音,同时注意钢尺振动的快慢,改变钢尺伸出桌边的长度,再次拨动,使钢尺每次的振动幅度大致相同.实验发现:尺子伸出桌面的长度越长振动越 ,发出声音的音调越 .
was to blame.
A.The parents as well as their child
B.Not the parents but their child
C.Neither the child nor his parents
D.Both the parents and their child