这件事本来可以预先告诉大家的。

Zhè jiàn shì běnlái kěyǐ yùxiān gàosu dàjiā de.

This matter actually could have been told to everyone in advance.

为了安全，我们需要预先检查所有设备。

Wèile ānquán, wǒmen xūyào yùxiān jiǎnchá suǒyǒu shèbèi.

For safety, we need to check all the equipment in advance.

参加活动的人请预先在网上报名。

Cānjiā huódòng de rén qǐng yùxiān zài wǎngshàng bàomíng.

People who take part in the event, please register online in advance.