Problem: Regression testing focuses on finding defects after a major code change has occurred. Specifically, it seeks to uncover software regressions, as degraded or lost features, including old bugs that have come back. Such regressions occur whenever software functionality that was previously working correctly, stops working as intended. Typically, regressions occur as an unintended consequence of program changes, when the newly developed part of the software collides with the previously existing code. Common methods of regression testing include re-running previous sets of test-cases and checking whether previously fixed faults have re-emerged. The depth of testing depends on the phase in the release process and the risk of the added features. They can either be complete, for changes added late in the release or deemed to be risky, or be very shallow, consisting of positive tests on each feature, if the changes are early in the release or deemed to be of low risk. Regression testing is typically the largest test effort in commercial software development, due to checking numerous details in prior software features, and even new software can be developed while using some old test-cases to test parts of the new design to ensure prior functionality is still supported.
What happens to software after a major change in code that leads to regression??
The answer is the following: stops working as intended

Problem: Over two centuries after the removal of the capital to Beijing, Nanjing was destined to become the capital of a Ming emperor one more time. After the fall of Beijing to Li Zicheng's rebel forces and then to the Manchu-led Qing dynasty in the spring of 1644, the Ming prince Zhu Yousong was enthroned in Nanjing in June 1644 as the Hongguang Emperor. His short reign was described by later historians as the first reign of the so-called Southern Ming dynasty.
What was Zhu Yousong's title?
The answer is the following: the Hongguang Emperor

Problem: On February 8, 1847, Doniphan continued his march with 924 men mostly from Missouri; he accompanied a train of 315 wagons of a large commercial caravan heading to the state capital. Meanwhile, the Mexican forces in the state had time to prepare a defense against the Americans. About 20 miles (32 km) north of the capital where two mountain ranges join from east to west is the only pass into the capital; known as Sacramento Pass, this point is now part of present-day Chihuahua City. The Battle of Sacramento was the most important battle fought in the state of Chihuahua because it was the sole defense for the state capital. The battle ended quickly because of some devastating defensive errors from the Mexican forces and the ingenious strategic moves by the American forces. After their loss at the Battle of Sacramento, the remaining Mexican soldiers retreated south, leaving the city to American occupation. Almost 300 Mexicans were killed in the battle, as well as almost 300 wounded. The Americans also confiscated large amounts of Mexican supplies and took 400 Mexican soldiers prisoners of war. American forces maintained an occupation of the state capital for the rest of the Mexican–American War.
Which was the most important battle fought in Chihuahua?
The answer is the following: The Battle of Sacramento

Problem: The convention followed by many British publishers (including scientific publishers, like Nature, magazines, like The Economist and New Scientist, and newspapers, like The Guardian and The Times) and U.S. newspapers is to use sentence-style capitalisation in headlines, where capitalisation follows the same rules that apply for sentences. This convention is usually called sentence case. It may also be applied to publication titles, especially in bibliographic references and library catalogues. Examples of global publishers whose English-language house styles prescribe sentence-case titles and headings include the International Organization for Standardization.
What is an alternative name for sentence-style capitalization?
The answer is the following:
sentence case