Context: There are seven suburbicarian sees: Ostia, Albano, Porto and Santa Rufina, Palestrina, Sabina and Mentana, Frascati and Velletri. Velletri was united with Ostia from 1150 until 1914, when Pope Pius X separated them again, but decreed that whatever cardinal bishop became Dean of the College of Cardinals would keep the suburbicarian see he already held, adding to it that of Ostia, with the result that there continued to be only six cardinal bishops.

Question: How many suburbicarian sees?
Answer: seven

Question: When were the two sees combined? 
Answer: 1150 until 1914

Question: Who separated them?
Answer: Pope Pius X

Question: What are the seven sees?
Answer: Ostia, Albano, Porto and Santa Rufina, Palestrina, Sabina and Mentana, Frascati and Velletri

Question: What are the name of the eight suburbicarian sees?
Answer: Unanswerable

Question: Which two sees were united from 1250 to 1944?
Answer: Unanswerable

Question: What did Pope Pius II do to Velletri and Ostia in 1914?
Answer: Unanswerable

Question: How did Pope Pius X maintain only four cardinal bishops?
Answer: Unanswerable

Question: What suburbicarian would the President of the College of Cardinal keep in addition to that Velletri?
Answer: Unanswerable