Question: What early work of art did da Vinci paint in conjunction with Verrocchio?
About the article "Leonardo da Vinci", section "Early works".

Candidate passages:
 NOTE: This is a brief summary of Leonardo's early life and journals with particular emphasis on his introduction to science.
Condensed biography.
Leonardo da Vinci (April 15, 1452 – May 2, 1519) was born the illegitimate son of Messer Piero, a notary, and Caterina, a peasant woman.
His early life was spent in the region of Vinci, in the valley of the Arno River near Florence, firstly with his mother and in later childhood in the household of his father, grandfather and uncle Francesco.
His curiosity and interest in scientific observation were stimulated by his uncle Francesco, while his grandfather's keeping of journals set an example which he was to follow for most of his life, diligently recording in his own journals both the events of the day, his visual observations, his plans and his projects.
The journals of Leonardo contain matters as mundane as grocery lists and as remarkable as diagrams for the construction of a flying machine.
In 1466, Leonardo was sent to Florence to the workshop of the artist Verrocchio, in order to learn the skills of an artist.
At the workshop, as well as painting and drawing, he learnt the study of topographical anatomy.
He was also exposed to a very wide range of technical skills such as drafting, set construction, plasterworking, paint chemistry, and metallurgy.
Among the older artists whose work stimulated Leonardo's scientific interest was Piero della Francesca, then a man in his 60s, who was one of the earliest artists to systematically employ linear perspective in his paintings, and who had a greater understanding of the science of light than any other artist of his date.
While Leonardo's teacher, Verrocchio, largely ignored Piero's scientifically disciplined approach to painting, Leonardo and Domenico Ghirlandaio, who also worked at Verrocchio's workshop, did not.
Two of Leonardo's earliest paintings, both scenes of the "Annunciation" show his competent understanding of the linear perspective.
Leonardo was profoundly observant of nature, his curiosity having been stimulated in early childhood by his discovery of a deep cave in the mountains and his intense desire to know what lay inside.
His earliest dated drawing, 1473, is of the valley of the Arno River, where he lived.
It displays some of the many scientific interests that were to obsess him all his life, in particular geology and hydrology. 
Andrea del Verrocchio was a sculptor, goldsmith and painter who ran a large and successful workshop in Florence in the second half of the 15th century.
Among his apprentices and close associates were the painters Botticelli, Botticini, Lorenzo di Credi and Leonardo da Vinci.
Verrocchio was not himself a prolific painter and very few pictures are attributed to his hand, his fame lying chiefly in his sculptured works.
Verrocchio's paintings, as are typical of Florentine works of that date, are in tempera on wooden panel.
The technique of painting artworks in oil paint, previously used in Italy only for durable items like parade shields, was introduced to Florence by Dutch and Flemish painters and their imported works at around the date that this painting was created.
The painting "The Baptism of Christ" was, according to Antonio Billi (1515), commissioned by the Church of S. Salvi, and was later transferred to the Vallumbrosan Sisterhood in Santa Verdiana.
In 1810 it entered the collection of the Accademia and passed to the Uffizi in 1959.
In the 16th century the work was discussed in Giorgio Vasari's "Lives of the Painters" in the biographies of both Verrocchio and Leonardo da Vinci. 
This is a painting of the Biblical subject of the Annunciation, by the Italian Renaissance artists Leonardo da Vinci and Andrea del Verrocchio, dating from circa 1472–1475 and housed in the Uffizi gallery of Florence, Italy.
The subject matter is drawn from the Gospel of Luke, Chapter 1, verses 26-39 and depicts the angel Gabriel, sent by God to announce to a virgin, Mary, that she would miraculously conceive and give birth to a son, to be named Jesus, and to be called "the Son of God" whose reign would never end.
The subject was very popular for artworks and had been depicted many times in the art of Florence, including several examples by the Early Renaissance painter Fra Angelico.
The details of it commission and its early history remain obscure.
In 1867, following Gustav Waagen methods, Baron Liphart identified this "Annunciation", newly arrived in the Uffizi Gallery from a xonvent near Florence, as by the young Leonardo, still working in the studio of his master Verrocchio.
The painting has since been attributed to different artists, including Leonardo and Verrocchio's contemporary Domenico Ghirlandaio.
It was more recently determined to be a collaboration between Leonardo and his master Verrocchio, with whom Leonardo collaborated on the "Baptism of Jesus". 
  1470: Carlo Crivelli paints the altarpiece (1470–71) for the church of San Francesco in Gualdo Tadino, on the border of Umbria, near Fabriano, Italy  1470: Cosimo Rosselli paints "Madonna and Child"  1470: Cosimo Tura paints "Saint Jerome"  1473: Francesco del Cossa paints the Griffoni Polyptych.
1474: Ercole de' Roberti paints "St. Jerome in the Wilderness"  1474-5: Andrea del Verrocchio assisted by Leonardo da Vinci paints "The Baptism of Christ"  c.1474-8: Leonardo da Vinci paints "Ginevra de' Benci"  1475: Leonardo da Vinci paints "The Annunciation"  1475: Andrea Mantegna completes a decade's work on the frescoes in the Camera degli Sposi in the Ducal palace, Mantua, Lombardy  c.1475: Antonio del Pollaiolo completes painting "Saint Sebastian" for the Pucci Chapel of Santissima Annunziata, Florence and paints "Hercules and the Hydra" and (probably during this decade) "Apollo and Daphne"  1478: Leonardo da Vinci paints either "The Benois Madonna" or the "Madonna with the Carnation"  
In 1466, at the age of fourteen, Leonardo was apprenticed to the artist Andrea di Cione, known as Verrocchio, whose workshop was "one of the finest in Florence".
Other famous painters apprenticed or associated with the workshop include Domenico Ghirlandaio, Perugino, Botticelli, and Lorenzo di Credi.
Leonardo would have been exposed to both theoretical training and a vast range of technical skills including drafting, chemistry, metallurgy, metal working, plaster casting, leather working, mechanics and carpentry as well as the artistic skills of drawing, painting, sculpting and modelling.
Much of the painted production of Verrocchio's workshop was done by his employees.
According to Vasari, Leonardo collaborated with Verrocchio on his "The Baptism of Christ", painting the young angel holding Jesus' robe in a manner that was so far superior to his master's that Verrocchio put down his brush and never painted again.
On close examination, the painting reveals much that has been painted or touched-up over the tempera using the new technique of oil paint, with the landscape, the rocks that can be seen through the brown mountain stream and much of the figure of Jesus bearing witness to the hand of Leonardo.
Leonardo may have been the model for two works by Verrocchio: the bronze statue of "David" in the Bargello and the Archangel Raphael in "Tobias and the Angel".
By 1472, at the age of twenty, Leonardo qualified as a master in the Guild of St Luke, the guild of artists and doctors of medicine, but even after his father set him up in his own workshop, his attachment to Verrocchio was such that he continued to collaborate with him.
Leonardo's earliest known dated work is a drawing in pen and ink of the Arno valley, drawn on August 5, 1473.