This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: Some opponents further claim that affirmative action has undesirable side-effects and that it fails to achieve its goals. They argue that it hinders reconciliation, replaces old wrongs with new wrongs, undermines the achievements of minorities, and encourages groups to identify themselves as disadvantaged, even if they are not. It may increase racial tension and benefit the more privileged people within minority groups at the expense of the disenfranchised within better-off groups (such as lower-class whites and Asians).There has recently been a strong push among American states to ban racial or gender preferences in university admissions, in reaction to the controversial and unprecedented decision in Grutter v. Bollinger. In 2006, nearly 60% of Michigan voters decided to ban affirmative action in university admissions. Michigan joined California, Florida, Texas, and Washington in banning the use of race or sex in admissions considerations. Some opponents believe, among other things, that affirmative action devalues the accomplishments of people who belong to a group it's supposed to help, therefore making affirmative action counter-productive. Furthermore, opponents of affirmative action claim that these policies dehumanize individuals and applicants to jobs or school are judged as members of a group without consideration for the individual person.
Other than failing to achieve its goal, what else do people who agree with affirmative action claim it has?

Passage: The Standard Model groups matter particles into three generations, where each generation consists of two quarks and two leptons. The first generation is the up and down quarks, the electron and the electron neutrino; the second includes the charm and strange quarks, the muon and the muon neutrino; the third generation consists of the top and bottom quarks and the tau and tau neutrino. The most natural explanation for this would be that quarks and leptons of higher generations are excited states of the first generations. If this turns out to be the case, it would imply that quarks and leptons are composite particles, rather than elementary particles.
What model has two generations?

Passage: The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and the eastern part. The thin northern fringe of the desert receives more winter cloudiness and rainfall due to the arrival of low pressure systems over the Mediterranean Sea along the polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from 100 mm (3,93 in) to 250 mm (9,84 in). For example, Biskra, Algeria and Ouarzazate, Morocco are found in this zone. The southern fringe of the desert along the border with the Sahel receives summer cloudiness and rainfall due to the arrival of the Intertropical Convergence Zone from the south and the annual average rainfall ranges from 100 mm (3,93 in) to 250 mm (9,84 in). For example, Timbuktu, Mali and Agadez, Niger are found in this zone. The vast central hyper-arid core of the desert is virtually never affected by northerly or southerly atmospheric disturbances and permanently remains under the influence of the strongest anticyclonic weather regime and the annual average rainfall can drop to less than 1 mm (0.04 in). In fact, most of the Sahara receives less than 20 mm (0.79 in). Of the 9,000,000 km2 of desert land in the Sahara, an area of about 2,800,000 km2 (about 31% of the total area) receives an annual average rainfall amount of 10 mm (0.39 in) or less, while some 1,500,000 km2 (about 17% of the total area) receive an average of 5 mm or less. The annual average rainfall is virtually zero over a wide area of some 1,000,000 km2 in the eastern Sahara comprising deserts of Libya, Egypt and Sudan (Tazirbu, Kufra, Dakhla, Kharga, Farafra, Siwa, Asyut, Sohag, Luxor, Aswan, Abu Simbel, Wadi Halfa) where the long-term mean approximates 0.5 mm per year. The rainfall is very unreliable and erratic in the Sahara as it may vary considerably year by year. In full contrast to the negligible annual rainfall amounts, the annual rates of potential evaporation are extraordinarily high, roughly ranging from 2,500 mm/year to more than 6,000 mm/year in the whole desert. Nowhere else on Earth has air been found as dry and evaporative as in the Sahara region. With such an evaporative power, the Sahara can only be desiccated and dried out further more and the moisture deficit is tremendous.

what is nearly non existent across the Sahara?