silk 033中文迅雷链接
It was said was how the Chinese first raised silk...
D 本句中的it为形式主语,真正的主语是后面的由that 引导的主语从句that that was how the Chinese first raised silk worms,在...
D 本句中的it为形式主语,真正的主语是后面的由that 引导的主语从句that that was how the Chinese first raised silk worms,在...