The police and other city officials do not have simple explanations for the increase.

In this case it was much too simple an explanation.

Of course there was a simple explanation for the whole thing.

However, this seems to have been too simple an explanation.

There might be a simple explanation for whatever you've been told.

But I still feel there must be a simple explanation.

There was almost certainly a simple explanation, she told herself.

That would be the simple explanation, and the most likely one too.

Ask them about it, and they have a simple explanation.

Yet, since it had happened, there must be a simple explanation.