Question

1. You should not miss breakfast.
2. You should not skip breakfast.
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Are both the same? What is the diffference?

3. Stand in a row.
4. Stand in row.
5. stand in rows.
6. stand in two rows.

(Can we use the expressions above?)

Answer 1

1 and 2 mean the same thing, yes.

#4 is not good. #5 is too vague; it doesn't say how many rows, so is confusing. #3 and #6 are fine, and specific (one row, two rows).