Problem: The Gregorian reform contained two parts: a reform of the Julian calendar as used prior to Pope Gregory XIII's time and a reform of the lunar cycle used by the Church, with the Julian calendar, to calculate the date of Easter. The reform was a modification of a proposal made by Aloysius Lilius. His proposal included reducing the number of leap years in four centuries from 100 to 97, by making 3 out of 4 centurial years common instead of leap years. Lilius also produced an original and practical scheme for adjusting the epacts of the moon when calculating the annual date of Easter, solving a long-standing obstacle to calendar reform.
How many parts did the Gregorian calendar reform have?
The answer is the following: two parts

Problem: These territories are sometimes referred to as the Països Catalans (Catalan Countries), a denomination based on cultural affinity and common heritage, that has also had a subsequent political interpretation but no official status. Various interpretations of the term may include some or all of these regions.
What are the Paisos Catalans
The answer is the following: Catalan Countries

Problem: It is thought that annelids were originally animals with two separate sexes, which released ova and sperm into the water via their nephridia. The fertilized eggs develop into trochophore larvae, which live as plankton. Later they sink to the sea-floor and metamorphose into miniature adults: the part of the trochophore between the apical tuft and the prototroch becomes the prostomium (head); a small area round the trochophore's anus becomes the pygidium (tail-piece); a narrow band immediately in front of that becomes the growth zone that produces new segments; and the rest of the trochophore becomes the peristomium (the segment that contains the mouth).
What do annelids' larvae live like?
The answer is the following: plankton

Problem: The process of making beer is known as brewing. A dedicated building for the making of beer is called a brewery, though beer can be made in the home and has been for much of its history. A company that makes beer is called either a brewery or a brewing company. Beer made on a domestic scale for non-commercial reasons is classified as homebrewing regardless of where it is made, though most homebrewed beer is made in the home. Brewing beer is subject to legislation and taxation in developed countries, which from the late 19th century largely restricted brewing to a commercial operation only. However, the UK government relaxed legislation in 1963, followed by Australia in 1972 and the US in 1978, allowing homebrewing to become a popular hobby.
What is a building called that is used for making beer?
The answer is the following:
a brewery