What links are there between sentences in the following?

They can also program the signs to flip between several sentences at specific intervals.

Most style guides recommend only a single space between sentences.

The relationship between sentences and propositions is a serious philosophical problem.

But between smiles and sentences, his eyes went back to the man with the orange hair.

No one has better calculated the needed breathing space between musical sentences.

"I don't hope," he said, pausing for breath between sentences of no more than a few words.

In the hope of preventing more questions, she barely took a breath between sentences.

Between sentences, Marie had managed to eat half of her salad.

Many experts now say that additional space is not required or desirable between sentences.