All doubts cleared at one go

Basically when i was attempting 200-401 mock exams, i had no doubts at all. This was because practice on these questions on a regular basis clears the doubts on it own. So i was weak in this particular topic - Maintain Appropriate End-Devices and Industrial Network Infrastructure Devices which was of 17% weightage. I wanted to master it because of its weightage. I could through practice and i achieved 85% in the Managing Industrial Networks with Cisco Networking Technologies certification exam luckily.