1. I don't think so.
2. I beg to differ.
3. I'm afraid I don't agree.
4. I'm not so sure about that.
5. That's not how I see it.
6. Not necessarily.
7. Yes, but... [say your opinion]
8. On the contrary.
9. (very informal) No way!
10. (very strong) I totally disagree.

Fact
The weakest muscle in the human body is the stapedius muscle which is located in the middle ear. Its only function is to move the 3 millimeters (1/8-inch) stirrup bone a 1/2-millimeter (1/16-inch).      .. More >>