A group of Chinese guests, who are the first ________ from the new agreement on tourism between China and Switzerland, were given a warm welcome in Geneva(日内瓦) last Saturday.

A．benefited

B．benefiting

C．to be benefited

D．to benefit

架子鼓是一种打击乐器，雏形起源于中国，最早可追溯到明朝时期。如图所示，当用大小不同的力敲击时，发出声音的       （选填“音调”、“响度”或“音色”）不同。