Problem: The Gregorian calendar is a solar calendar. A regular Gregorian year consists of 365 days, but as in the Julian calendar, in a leap year, a leap day is added to February. In the Julian calendar a leap year occurs every 4 years, but the Gregorian calendar omits 3 leap days every 400 years. In the Julian calendar, this leap day was inserted by doubling 24 February, and the Gregorian reform did not change the date of the leap day. In the modern period, it has become customary to number the days from the beginning of the month, and February 29th is often considered as the leap day. Some churches, notably the Roman Catholic Church, delay February festivals after the 23rd by one day in leap years.
On what day did both the Julian and Gregorian calendars add leap day?
The answer is the following: 24 February

Problem: Court presentations of aristocratic young ladies to the monarch took place at the palace from the reign of Edward VII. These young women were known as débutantes, and the occasion—termed their "coming out"—represented their first entrée into society. Débutantes wore full court dress, with three tall ostrich feathers in their hair. They entered, curtsied, and performed a choreographed backwards walk and a further curtsy, while manoeuvring a dress train of prescribed length. (The ceremony, known as an evening court, corresponded to the "court drawing rooms" of Victoria's reign.) After World War II, the ceremony was replaced by less formal afternoon receptions, usually without choreographed curtsies and court dress.
What was the occasion where debutantes were presented to society called?
The answer is the following: "coming out"

Problem: The abdomen is the largest tagma of the insect, which typically consists of 11–12 segments and is less strongly sclerotized than the head or thorax. Each segment of the abdomen is represented by a sclerotized tergum and sternum. Terga are separated from each other and from the adjacent sterna or pleura by membranes. Spiracles are located in the pleural area. Variation of this ground plan includes the fusion of terga or terga and sterna to form continuous dorsal or ventral shields or a conical tube. Some insects bear a sclerite in the pleural area called a laterotergite. Ventral sclerites are sometimes called laterosternites. During the embryonic stage of many insects and the postembryonic stage of primitive insects, 11 abdominal segments are present. In modern insects there is a tendency toward reduction in the number of the abdominal segments, but the primitive number of 11 is maintained during embryogenesis. Variation in abdominal segment number is considerable. If the Apterygota are considered to be indicative of the ground plan for pterygotes, confusion reigns: adult Protura have 12 segments, Collembola have 6. The orthopteran family Acrididae has 11 segments, and a fossil specimen of Zoraptera has a 10-segmented abdomen.
The abdomen is less strong than the thorax and what?
The answer is the following: head

Problem: The evolution of Proto-Greek should be considered within the context of an early Paleo-Balkan sprachbund that makes it difficult to delineate exact boundaries between individual languages. The characteristically Greek representation of word-initial laryngeals by prothetic vowels is shared, for one, by the Armenian language, which also seems to share some other phonological and morphological peculiarities of Greek; this has led some linguists to propose a hypothetical closer relationship between Greek and Armenian, although evidence remains scant.
What other language has this same trait ?
The answer is the following:
word-initial laryngeals by prothetic vowels is shared, for one, by the Armenian language