玻璃缸的水中有金鱼，用细棍敲击一下缸沿，金鱼立即受惊，这时金鱼接收到声波的主要途径是[ ]

A．发声体﹣介质﹣耳朵

B．耳朵﹣发声体﹣介质

C．发声体﹣耳朵﹣介质

D．耳朵﹣介质﹣发声体

He said he would arrive before seven, and _____. [ ]

A. he did

B. did he

C. he had

D. had he