Statements : Some uniforms are covers. All covers are papers. All papers are bags. Conclusions : I. All covers are bags. II. Some bags are covers, papers and uniforms. III. Some uniforms are not papers.

The correct answer is $\boxed{\text{B. Only I and II follow}}$.

Let’s go through each of the options and explain why they are or are not correct.

• Option A: Only I follows. This is not correct, because II does not follow. We know that some uniforms are covers, and all covers are papers. However, we do not know that all covers are uniforms. For example, all squares are rectangles, but not all rectangles are squares. Therefore, it is possible that there are some bags that are covers and papers, but not uniforms.
• Option B: Only I and II follow. This is correct. We know that some uniforms are covers, and all covers are papers. Therefore, some uniforms are papers. We also know that all papers are bags. Therefore, some uniforms are bags.
• Option C: Only III follows. This is not correct, because I does not follow. We know that some uniforms are covers, and all covers are papers. However, we do not know that some uniforms are not papers. For example, all squares are rectangles, but not all rectangles are squares. Therefore, it is possible that all uniforms are papers.
• Option D: All I, II and III follow. This is not correct, because III does not follow. We know that some uniforms are covers, and all covers are papers. However, we do not know that some uniforms are not papers. For example, all squares are rectangles, but not all rectangles are squares. Therefore, it is possible that all uniforms are papers.
• Option E: None of these. This is not correct, because B is correct.

Therefore, the correct answer is $\boxed{\text{B. Only I and II follow}}$.