（3分）如图所示，甲为常见的高音喇叭和医用听诊器，将它们制成这种形状，是为了减小声音的散失从而增大声音的      ；而在有些地方可以看到乙图所示的标牌，它的意思是      。从而达到在      处减弱噪声的目的。

Education reform，         the Chinese government attaches great importance，has

attracted a lot of public attention．

A．in which

B．to which

C．in that

D．to that