瀑布从悬崖上倾泻而下，形成一片壮观的景象。

The waterfall ___cascaded down the cliff, creating a spectacular sight.

消息在人群中迅速传播，引发了连锁反应。

The news ___cascaded through the crowd, triggering a chain reaction.

系统将用户请求层层传递到各个处理模块。

The system ___cascades the user request through multiple processing modules.