Question

There are three sentences in the speech bubble on the left.

There are three sentences in the speech balloon on the left.

There are three sentences in the balloon on the left.

There are three sentences in the bubble on the left.
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Are the expressions all correct? Which expression is commonly used?

Answer 1

Of these, the one below would be the most commonly used.

There are three sentences in the speech balloon on the left.

Bubble is not usually used in this context, and to use bubble or ballon alone without "speech" would make the meaning unclear.