文字稿:

They have a tough mission ahead.

Thousands of members of the Saudi security forces have been taking part in a parade ahead of the world's biggest religious gathering.

The Hajj involves over 2 million Muslim pilgrims. It's a ritual that's designed to promote Islamic brotherhood.

With tensions simmering in the region, particularly in Lebanon and Syria, the logistics are even more complicated than usual.

Vocabulary 詞匯:

mission 使命，任務

parade 閱兵，列隊游行

pilgrims 朝圣

simmering 一觸即發(fā)的

logistics 安保措施和步驟