TASK DEFINITION: In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
PROBLEM: Passage: Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest living relatives are the hippopotamuses, having diverged about 40 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have split apart around 34 million years ago.  Whales consist of eight extant families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), Eschrichtiidae (the grey whale), Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales).
Whales are creatures of the open ocean; they feed, mate, give birth, suckle and raise their young at sea. So extreme is their adaptation to life underwater that they are unable to survive on land. Whales range in size from the 2.6 metres (8.5 ft) and 135 kilograms (298 lb) dwarf sperm whale to the 29.9 metres (98 ft) and 190 metric tons (210 short tons) blue whale, which is the largest creature that has ever lived. The sperm whale is the largest toothed predator on earth. Several species exhibit sexual dimorphism, in that the females are larger than males. Baleen whales have no teeth; instead they have plates of baleen, a fringe-like structure used to expel water while retaining the krill and plankton which they feed on. They use their throat pleats to expand the mouth to take in huge gulps of water. Balaenids have heads that can make up 40% of their body mass to take in water. Toothed whales, on the other hand, have conical teeth adapted to catching fish or squid. Baleen whales have a well developed sense of "smell", whereas toothed whales have well-developed hearing − their hearing, that is adapted for both air and water, is so well developed that some can survive even if they are blind. Some species, such as sperm whales, are well adapted for diving to great depths to catch squid and other favoured prey. 
Question: What are the types of whales that use throat pleats to expand the mouth?

SOLUTION: Baleen.

PROBLEM: Passage: Bach's early cantatas are Choralkonzerte (chorale concertos) in the style of the 17th century, different from the recitative and aria cantata format associated with Neumeister that Bach started to use for church cantatas in 1714. Wolff points out the relation of Bach's early cantatas to works by Dieterich Buxtehude, with whom Bach had studied in Lübeck. Christ lag in Todes Banden shows similarities to a composition of Johann Pachelbel based on the same Easter chorale. Although there is no evidence that Bach and Pachelbel met, Bach grew up in Thuringia while Pachelbel was based in the same region, and Bach's elder brother and teacher Johann Christoph Bach studied with Pachelbel in Erfurt. Another of Pachelbel's works appears to be referenced in the early Bach cantata, Nach dir, Herr, verlanget mich, BWV 150, and there has been recent speculation that Bach wanted to pay tribute to Pachelbel after his death in 1706.The texts for the early cantatas were drawn mostly from biblical passages and hymns. Features characteristic of his later cantatas, such as recitatives and arias on contemporary poetry, were not yet present, although Bach may have heard them in oratorios by Buxtehude, or even earlier. Instead, these early cantatas include 17th-century elements such as motets and chorale concertos. They often begin with an instrumental sinfonia or sonata (sonatina). The following table lists the seven extant works composed by Bach until 1708, when he moved on to the Weimar court.
Bach uses the limited types of instruments at his disposal for unusual combinations, such as two recorders and two viole da gamba in the funeral cantata Gottes Zeit ist die allerbeste Zeit, also known as Actus Tragicus. He uses instruments of the continuo group as independent parts, such as a cello in Nach dir, Herr, verlanget mich and a bassoon in Der Herr denket an uns. The cantata for the inauguration of a town council is richly scored for trumpets, woodwinds and strings. Wolff notes:
The overall degree of mastery by which these early pieces compare favourably with the best church compositions from the first decade of the eighteenth century ... proves that the young Bach did not confine himself to playing organ and clavier, but, animated by his Buxtehude visit, devoted considerable time and effort to vocal composition. The very few such early works that exist, each a masterpiece in its own right, must constitute a remnant only ... of a larger body of similar compositions.
The Bach scholar Richard D. P. Jones notes in The Creative Development of Johann Sebastian Bach:
"His remarkable flair for text illustration is evident even in the early cantatas, particularly the two finest of them, the Actus tragicus, BWV 106, and Christ lag in Todes Banden, BWV 4. We already sense a powerful mind behind the notes in the motivic unity of the early cantatas, in the use of reprise to bind their mosaic forms together ...". 
Question: What often begin with an instrumental sinfonia or sonata?

SOLUTION: cantatas.

PROBLEM: Passage: Tchaikovsky remained abroad for a year after the disintegration of his marriage. During this time, he completed Eugene Onegin, orchestrated his Fourth Symphony, and composed the Violin Concerto. He returned briefly to the Moscow Conservatory in the autumn of 1879. For the next few years, assured of a regular income from von Meck, he traveled incessantly throughout Europe and rural Russia, mainly alone, and avoided social contact whenever possible. During this time, Tchaikovsky's foreign reputation grew and a positive reassessment of his music also took place in Russia, thanks in part to Russian novelist Fyodor Dostoyevsky's call for "universal unity" with the West at the unveiling of the Pushkin Monument in Moscow in 1880. Before Dostoyevsky's speech, Tchaikovsky's music had been considered "overly dependent on the West". As Dostoyevsky's message spread throughout Russia, this stigma toward Tchaikovsky's music evaporated. An unprecedented acclaim for him even drew a cult following among the young intelligentsia of Saint Petersburg, including Alexandre Benois, Léon Bakst and Sergei Diaghilev.Two musical works from this period stand out. With the Cathedral of Christ the Saviour nearing completion in Moscow in 1880, the 25th anniversary of the coronation of Alexander II in 1881, and the 1882 Moscow Arts and Industry Exhibition in the planning stage, Nikolai Rubinstein suggested that Tchaikovsky compose a grand commemorative piece. Tchaikovsky agreed and finished it within six weeks. He wrote to Nadezhda von Meck that this piece, the 1812 Overture, would be "very loud and noisy, but I wrote it with no warm feeling of love, and therefore there will probably be no artistic merits in it". He also warned conductor Eduard Nápravník that "I shan't be at all surprised and offended if you find that it is in a style unsuitable for symphony concerts". Nevertheless, the overture became, for many, "the piece by Tchaikovsky they know best"., particularly well-known for the use of cannon in the scores.On 23 March 1881, Nikolai Rubinstein died in Paris. That December, Tchaikovsky started work on his Piano Trio in A minor, "dedicated to the memory of a great artist". First performed privately at the Moscow Conservatory on the first anniversary of Rubinstein's death, the piece became extremely popular during the composer's lifetime; in November 1893, it would become Tchaikovsky's own elegy at memorial concerts in Moscow and St. Petersburg. 
Question: What is the full name of the person that Tchaikovsky was assured a regular income from for a few years?

SOLUTION:
Nadezhda von Meck.