他对导致这场灾难的事件毫无记忆。

He had no memory of the incidents that ___led ___up ___to the disaster.

分析导致这场危机的因素很重要。

It is important to analyze the factors that have ___led ___up ___to this crisis.

导致协议达成的一系列会议至关重要。

The series of meetings that ___led ___up ___to the agreement were crucial.