The tour guide wore a dark shirt and cap as he pointed out the sign listing the rules to his young passengers .
Chances are slight that a tour guide is explaining the rules on a sign and is about to start a tour of a city .
It is probable that a tour guide is explaining the rules on a sign and is about to start a tour of a city .
Chances are slight that a tour guide is explaining the rules on a sign and is about to start a tour of a city .
A tour guide is explaining the rules on a sign and is about to start a tour of a city .