1. A is completely / totally / entirely different from B.
2. A and B are different in some/every way / respect / aspect.
3. A and B differ in.
4. A differs from B in.
5. The difference between A and B is/lies in/exists in.
6. Compared with/In contrast to/Unlike A, B.
7. A, on the other hand,/in contrast,/while/whereas B.
8. While it is generally believed that A , I believe B.
9. Despite their similarities, A and B are also different.
10. Both A and B . However, A on the other hand, B.
11. The most striking difference is that A, while B.