Read the sentences.
The tone of the speech was stern. The speaker called for hard work and determination.
Which is the best way to combine the sentences?
The tone of the speech was stern; the speaker called for hard work and determination.
The tone of the speech was stern; and the speaker called for hard work and determination.
The tone of the speech was stern . . . the speaker called for hard work and determination.
The tone of the speech was stern, the speaker called for hard work and determination.