15.I was always told that the three"P"s,patience,positive thinking and perseverance (毅力),were a sure path (41)tosuccess.But this advice does not always work as planned.My high school maths exam is one example.The exam,(42)whichwas originally to be held in our classroom,(43)was changed(change) to the library at the last minute.This,(44)however,didn't bother me because maths had always been my strongest subject.I patiently walked to the library,took my seat and did some deep breathing to help relax (45)myself.But my mood quickly changed when I saw (46)thefirst question.I had no idea how to do it.I tried to stay positive and persevered (47)until/tillI finally found the solution.With the problem(48)solved(solve),I felt proud of my achievement.(49)Unfortunately(fortunate),I then noticed that I had just 10minutes left (50)to complete(complete) the rest!