4. I think you should (consider) ---------- your decision.
a. Diconsider
b. Reconsider
c. Unconsider
5. I'm (certain) ---------- about the time he is coming.
a. Uncertain
b. Incertain
c. Discertain
6. Its (legal)---------- to speak on the phone when you are driving.
a. Unlegal
b. Inlegal
c. Illegal