The penny dropped one day when I heard my son sitting on the toilet.

有一天我听到我的儿子坐在马桶上说“piping！

youdao

The penny dropped about their true relationship as they talked about their childhoods during lunch.

当他们聊起了各自的童年，两人真正的关系终于真相大白。

youdao

The worst case scenario from a penny dropped from a great height is a slight sting.

事实上，一分硬币从高空坠落所能造成的最大创伤也不过是轻微的刺痛。

youdao

It was--having seen this very first pattern, the penny dropped almost immediately.

NPR: Pioneering DNA Forensics

Suddenly the penny dropped and things have really gathered pace recently.

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And regulators made sure that when the penny dropped, a sovereign debt crisis would become a banking crisis, because the Italian, Greek, Portuguese and Spanish banks were all stuffed to the gunnels with Italian, Greek, Portuguese and Spanish government debt.

BBC: The eurozone's borrowing costs may stay lethally high