Input: Madonna (entertainer)
In June 1986, Madonna released her third studio album, True Blue, which was inspired by and dedicated to Sean Penn. Rolling Stone magazine was generally impressed with the effort, writing that the album "sound[s] as if it comes from the heart". It resulted in three singles making it to number-one on the Billboard Hot 100: "Live to Tell", "Papa Don't Preach" and "Open Your Heart", and two more top-five singles: "True Blue" and "La Isla Bonita". The album topped the charts in over 28 countries worldwide, an unprecedented achievement at the time, and became her best-selling studio album of her career to this date with sales of 25 million. In the same year, Madonna starred in the critically panned film Shanghai Surprise, for which she was awarded the Golden Raspberry Award for "worst actress". She made her theatrical debut in a production of David Rabe's Goose and Tom-Tom; the film and play both co-starred Penn. The next year, Madonna was featured in the film Who's That Girl. She contributed four songs to its soundtrack, including the title track and "Causing a Commotion".

When was Madonna's third album released?
Output: June 1986

Input: Black people
In early 1991, non-Arabs of the Zaghawa tribe of Sudan attested that they were victims of an intensifying Arab apartheid campaign, segregating Arabs and non-Arabs (specifically people of sub-Saharan African descent). Sudanese Arabs, who controlled the government, were widely referred to as practicing apartheid against Sudan's non-Arab citizens. The government was accused of "deftly manipulat(ing) Arab solidarity" to carry out policies of apartheid and ethnic cleansing.

Where did these people live?
Output: Sudan

Input: Letter case
As briefly discussed in Unicode Technical Note #26, "In terms of implementation issues, any attempt at a unification of Latin, Greek, and Cyrillic would wreak havoc [and] make casing operations an unholy mess, in effect making all casing operations context sensitive […]". In other words, while the shapes of letters like A, B, E, H, K, M, O, P, T, X, Y and so on are shared between the Latin, Greek, and Cyrillic alphabets (and small differences in their canonical forms may be considered to be of a merely typographical nature), it would still be problematic for a multilingual character set or a font to provide only a single codepoint for, say, uppercase letter B, as this would make it quite difficult for a wordprocessor to change that single uppercase letter to one of the three different choices for the lower-case letter, b (Latin), β (Greek), or в (Cyrillic). Without letter case, a "unified European alphabet" – such as ABБCГDΔΕZЄЗFΦGHIИJ…Z, with an appropriate subset for each language – is feasible; but considering letter case, it becomes very clear that these alphabets are rather distinct sets of symbols.

Attempts to unify Latin, Greek, and Cyrillic would create which sort of problems?
Output: make casing operations an unholy mess

Input: Planck constant
There are both practical and theoretical difficulties in determining h. The practical difficulties can be illustrated by the fact that the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another. The most likely reason is that the measurement uncertainty for one (or both) of the methods has been estimated too low – it is (or they are) not as precise as is currently believed – but for the time being there is no indication which method is at fault.

Why does this difficulty occur?
Output:
it is (or they are) not as precise as is currently believed