Biblical Egypt

When the reader reaches to the beginning of every paragraph, they repeat whatever he, the reader, had said.

How? When he says, when Israel left Egypt, the paragraph that begins with those words, everyone repeats after him and say, then the reader reads the next few words, the house of Israel from a foreign nation, and everyone answers, until he gets to the next paragraph, which begins with the words, I love that the Lord should hear my voice in my supplications.

When he gets to that point, since this is the beginning of the paragraph, everyone repeats after him, and they say, the very same words, and so on.

Likewise, when he begins the paragraph, which begins with the words, praise God all over the nations, Since that is the beginning of the paragraph, they don't say Halaluka, but they do say Kol Ha'am Chosin.