I would be absolutely shocked to find out that any of the questions were fill in the blank type of answers. The sample test that the ABP has available is for the pediatric MOC exam, NOT the initial certification exam. I just ran through it and did not see any fill in the blank questions.
Here is the link – https://www.abp.org/abpwebsite/moc/ABP%20Demo/index.htm
Please make sure you went to the right place.
Also, know that there are FOUR sections for the pediatric initial certification exam (not 2). You have more breaks.
Also, KNOW the software, the table, the shortcuts, the ABP policies, etc. so that you can skip all of that on the big day and use that time for BREAKS. —> HUGE TIP!
Good luck.
– ashish