A sign prohibiting spitting.

Publicity slogans have the effect of being widely publicized, which will produce different contextual effects because of different places and objects.

1, don't spit! Add an exclamation point to emphasize the tone, which means warning, warning and prohibition. This means that it is non-negotiable and strictly enforced.

2, bite a small mouth, thousands of bacteria. This is an explanatory propaganda language to inform the "informed" about the harm of phlegm, so that the "informed" can realize its harm and consciously follow and implement it. It is a gentle reminder without strong emotions.

The first sentence is imperative, with a strong tone, a commanding tone, firm and serious.

The second declarative sentence is warm in tone, vivid and lively.