tīng / dào / zhè / ge / yì / wài / de / xiāo / xi / tā / yí / xià / zi / zhāng / kǒu / jié / shé / bù / zhī / dào / gāi / shuō / shén / me

听到这个意外的消息，他一下子张口结舌，不知道该说什么。

After hearing the unexpected news, he was suddenly left speechless and did not know what to say.