TASK DEFINITION: This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
PROBLEM: Passage: The redevelopment of the city was planned by Sir Patrick Abercrombie in his 1943 Plan for Plymouth whilst simultaneously working on the reconstruction plan for London. Between 1951 and 1957 over 1000 homes were completed every year mostly using innovative prefabricated systems of just three main types; by 1964 over 20,000 new homes had been built transforming the dense overcrowded and unsanitary slums of the pre-war city into a low density, dispersed suburbia. Most of the city centre shops had been destroyed and those that remained were cleared to enable a zoned reconstruction according to his plan. In 1962 the modernist high rise of the Civic Centre was constructed, an architecturally significant example of mid twentieth century civic slab-and-tower set piece allowed to fall into disrepair by its owner Plymouth City Council but recently grade II listed by English Heritage to prevent its demolition. Question: In the period 1951-1957, how many new houses were constructed yearly in Plymouth?

SOLUTION: over 1000

PROBLEM: Passage: In military affairs, the use of infantry with specialised roles increased. Along with the still-dominant heavy cavalry, armies often included mounted and infantry crossbowmen, as well as sappers and engineers. Crossbows, which had been known in Late Antiquity, increased in use partly because of the increase in siege warfare in the 10th and 11th centuries.[AB] The increasing use of crossbows during the 12th and 13th centuries led to the use of closed-face helmets, heavy body armour, as well as horse armour. Gunpowder was known in Europe by the mid-13th century with a recorded use in European warfare by the English against the Scots in 1304, although it was merely used as an explosive and not as a weapon. Cannon were being used for sieges in the 1320s, and hand-held guns were in use by the 1360s. Question: What led to the increased use of armor in the 12th century?

SOLUTION: The increasing use of crossbows

PROBLEM: Passage: 23rd Street is another main numbered street in Manhattan. It begins at FDR Drive and ends at Eleventh Avenue. Its length is 3.1 km/1.9m. It has two-way travel. On 23rd Street there are five local subway stations: Question: What is the length of 23rd Street in kilometers?

SOLUTION:
3.1 km