The group there stopped on a dune crest, waved.

那里的一群人停在沙丘顶上，挥手致意。

Where the two groups had met at the dune crest, a dust cloud partly obscured violent motion.

在两组人在沙丘峰相遇的地方，尘埃云部分掩盖了剧烈的运动。