Jìrán / dàjiā / dōu / yǐjīng / zhǔnbèi / hǎo / le / wǒmen / jiù / yīnggāi / chènrèdǎtiě / mǎshàng / kāishǐ

既然大家都已经准备好了，我们就应该趁热打铁，马上开始。

Since everyone is ready, we should strike while the iron is hot and start right away.