Question: When did the chemical attacks happen in 2017 in the country known for its Muslims and the people who traded slaves into the Middle East?

full_context: Document 1: Guinea-Bissau: Guinea-Bissau is a member of the United Nations, African Union, Economic Community of West African States, Organisation of Islamic Cooperation, the Latin Union, Community of Portuguese Language Countries, La Francophonie and the South Atlantic Peace and Cooperation Zone.
Document 2: Rif Dimashq offensive (March–August 2013): On 21 August, an alleged chemical attack on the Ghouta region claimed lives of hundreds of people, both civilians and rebels. Estimates of dead varied from 355 up to 1,429.On 22 August, according to the Syrian opposition, the Syrian Army launched a new offensive against rebel positions in Rif Dimashq. The Army entered Erbine, Harasta, Jobar, Zamalka and Ain Tarma, but without taking full control. They did however capture strategic points.
Document 3: Syria: Syria (Arabic: سوريا ‎ Sūriyā), officially known as the Syrian Arab Republic (Arabic: الجمهورية العربية السورية ‎ al - Jumhūrīyah al - ʻArabīyah as - Sūrīyah) is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the west, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest. Syria's capital and largest city is Damascus. A country of fertile plains, high mountains, and deserts, Syria is home to diverse ethnic and religious groups, including Syrian Arabs, Greeks, Armenians, Assyrians, Kurds, Circassians, Mandeans and Turks. Religious groups include Sunnis, Christians, Alawites, Druze, Isma'ilis, Mandeans, Shiites, Salafis, Yazidis, and Jews. Sunni make up the largest religious group in Syria.
Document 4: March 2012 Damascus bombings: The March 2012 Damascus bombings were two large car bombs that exploded in front of the air intelligence and criminal security headquarters in the Syrian capital of Damascus. At least 27 people were reported killed and over a 140 injured in the fourth major bombing since the beginning of the uprising and the second in the city. As in previous cases, the opposition blamed the government for orchestrating attacks, while the government placed the blame on terrorists and foreign groups.
Document 5: Syria: Sunni Muslims make up between 69–74% of Syria's population and Sunni Arabs account for 59–60% of the population. Most Kurds (8.5%) and most Turkoman (3%) are Sunni and account for the difference between Sunnis and Sunni Arabs, while 13% of Syrians are Shia Muslims (particularly Alawite, Twelvers, and Ismailis but there are also Arabs, Kurds and Turkoman), 10% Christian (the majority are Antiochian Greek Orthodox, the rest are Syrian Orthodox, Greek Catholic and other Catholic Rites, Assyrian Church of the East, Armenian Orthodox, Protestants and other denominations), and 3% Druze. Druze number around 500,000, and concentrate mainly in the southern area of Jabal al-Druze.President Bashar al-Assad's family is Alawite and Alawites dominate the government of Syria and hold key military positions. In May 2013, SOHR stated that out of 94,000 killed during the Syrian Civil War, at least 41,000 were Alawites.Christians (2.5 million), a sizable number of whom are found among Syria's population of Palestinian refugees, are divided into several sects: Chalcedonian Antiochian Orthodox make up 45.7% of the Christian population; the Catholics (Melkite, Armenian Catholic, Syriac Catholic, Maronite, Chaldean Catholic and Latin) make up 16.2%; the Armenian Apostolic Church 10.9%, the Syriac Orthodox make up 22.4%; Assyrian Church of the East and several smaller Christian denominations account for the remainder. Many Christian monasteries also exist. Many Christian Syrians belong to a high socio-economic class.
Document 6: Religion in Lebanon: Lebanon has several different main religions. The country has the most religiously diverse society of all states within the Middle East, comprising 18 recognized religious sects. The main two religions are Islam (Shia and Sunni) with 54% of followers and Christianity (the Maronite Church, the Greek Orthodox Church, the Melkite Greek Catholic Church, the Protestant Church, the Armenian Apostolic Church) with 40.4% of followers. There is also the Druze minority religion, which under the Lebanese political division (Parliament of Lebanon Seat Allocation) the Druze community is designated as one of the five Lebanese Muslim communities (Sunni, Shia, Druze, Alawi, and Ismaili).
Document 7: Douma chemical attack: European Union – In a statement, the EU said "the evidence points towards yet another chemical attack by the regime" and "it is a matter of grave concern that chemical weapons continue to be used, especially on civilians. The European Union condemns in the strongest terms the use of chemical weapons and calls for an immediate response by the international community". It also called for the United Nations Security Council to identify the perpetrators and for Russia and Iran to influence Assad against launching such attacks. United Nations – On 10 April 2018, the United Nations Security Council failed to adopt three competing resolutions on an inquiry into the chemical attack, with Russia and the United States clashing over the issue and exchanging military threats.The World Health Organization released a statement, with a reference to outside medical sources, that 43 people died while suffering "symptoms consistent with exposure to highly toxic chemicals."
Document 8: Guinea-Bissau: Guinea-Bissau was once part of the kingdom of Gabu, part of the Mali Empire; parts of this kingdom persisted until the 18th century. Other parts of the territory in the current country were considered by the Portuguese as part of their empire. Portuguese Guinea was known as the Slave Coast, as it was a major area for the exportation of African slaves by Europeans to the western hemisphere. Previously slaves had been traded by Arabs north to the northern part of Africa and into the Middle East.
Document 9: Guinea-Bissau: Guinea-Bissau was once part of the kingdom of Gabu, as well as part of the Mali Empire. Parts of this kingdom persisted until the 18th century, while a few others were under some rule by the Portuguese Empire since the 16th century. In the 19th century, it was colonized as Portuguese Guinea. Upon independence, declared in 1973 and recognised in 1974, the name of its capital, Bissau, was added to the country's name to prevent confusion with Guinea (formerly French Guinea). Guinea-Bissau has a history of political instability since independence, and no elected president has successfully served a full five-year term.
Document 10: Religion in Kyrgyzstan: Islam is the most widely held faith. Official sources estimated that 87,6 percent of the population is Muslim. The CIA World Factbook estimates 85%. Almost all the Muslims are Sunni; there are few Shia in the country (approximately one thousand). There are also a few Ahmadiyya Muslims, though unrecognised by the country. According to SARA, as of May 2007 there were 1,650 mosques, of which 1,623 were registered. There also were seven institutes for higher Islamic teaching.
Document 11: Central African Republic: During the 16th and 17th centuries slave traders began to raid the region as part of the expansion of the Saharan and Nile River slave routes. Their captives were slaved and shipped to the Mediterranean coast, Europe, Arabia, the Western Hemisphere, or to the slave ports and factories along the West and North Africa or South the Ubanqui and Congo rivers. In the mid 19th century, the Bobangi people became major slave traders and sold their captives to the Americas using the Ubangi river to reach the coast. During the 18th century Bandia-Nzakara peoples established the Bangassou Kingdom along the Ubangi River.
Document 12: Guinea-Bissau: Portuguese natives comprise a very small percentage of Guinea-Bissauans. After Guinea-Bissau gained independence, most of the Portuguese nationals left the country. The country has a tiny Chinese population. These include traders and merchants of mixed Portuguese and Chinese ancestry from Macau, a former Asian Portuguese colony.
Document 13: Religion in Syria: In Syria, Jews of both origins, numbering altogether fewer than 3,000 in 1987, are found. After a mass emigration in 1992, today fewer than 200 Jews live in Syria, mostly in the capital. Syrian Jews are Arabic-speaking and barely distinguishable from the Arabs around them. In Syria, as elsewhere, the degree to which Jews submit to the disciplines of their religion varies.
Document 14: Chemical weapon: Russia entered the CWC with the largest declared stockpile of chemical weapons. By 2010 the country had destroyed 18,241 tonnes at destruction facilities located in Gorny (Saratov Oblast) and Kambarka (Udmurt Republic), where operations have finished, and Shchuchye (Kurgan Oblast), Maradykovsky (Kirov Oblast), Leonidovka (Penza Oblast) while installations are under construction in Pochep (Bryansk Oblast) and Kizner (Udmurt Republic). By 2016, Russia destroyed around 94% of its chemical weapons, planning to completely destroy its remaining stockpile by the end of 2018. On September 27, 2017 Russia announced the destruction of the last batch of chemical weapons, completing the total destruction of its chemical arsenal, ahead of schedule.On March 4, 2018, Russia was alleged to have conducted a chemical attack in Salisbury, UK that left 5 injured including the alleged target of the attack, Sergei Skripal.
Document 15: Khan Shaykhun chemical attack: The Khan Shaykhun chemical attack took place on 4 April 2017 on the town of Khan Shaykhun in the Idlib Governorate of Syria. At the time of the attack, the town was under the control of Tahrir al - Sham, previously known as the al - Nusra Front.
ground_truth: 4 April
sub_queries: Who traded slaves into the Middle East? Answer: Arabs
What country is known for its Arabs and Muslims? Answer: Syria
when did the chemical attack in Syria happen 2017 Answer: 4 April