Question: At least how many tropical islands are found in middle leg of the journey from the continent Tekezé River is located to the Americas?

full_context: Document 1: Tekezé River: The Tekezé River rises in the central Ethiopian Highlands near Mount Qachen within Lasta, from where it flows west, north, then west again, forming the westernmost border of Ethiopia and Eritrea from the confluence of the Tomsa with the Tekezé at to the tripoint between the two countries and Sudan at . After entering northeastern Sudan at the tripoint it joins the Atbarah River, which is a tributary of the Nile. The Tekezé is perhaps the true upper course of the Atbarah, as the former follows the longer course prior to the confluence of the two rivers.
Document 2: Nile: The Nile (Arabic: النيل‎, written as al-Nīl; pronounced as an-Nīl) is a major north-flowing river in northeastern Africa, and is the longest river in Africa and the disputed longest river in the world (Brazilian government claims that the Amazon River is longer than the Nile). The Nile, which is about 6,650 km (4,130 mi) long, is an "international" river as its drainage basin covers eleven countries, namely, Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, Republic of the Sudan and Egypt. In particular, the Nile is the primary water source of Egypt and Sudan.The river Nile has two major tributaries, the White Nile and Blue Nile. The White Nile is considered to be the headwaters and primary stream of the Nile itself. The Blue Nile, however, is the source of most of the water and silt. The White Nile is longer and rises in the Great Lakes region of central Africa, with the most distant source still undetermined but located in either Rwanda or Burundi. It flows north through Tanzania, Lake Victoria, Uganda and South Sudan.  The Blue Nile begins at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet just north of the Sudanese capital of Khartoum.The northern section of the river flows north almost entirely through the Sudanese desert to Egypt, then ends in a large delta and flows into the Mediterranean Sea. Egyptian civilization and Sudanese kingdoms have depended on the river since ancient times. Most of the population and cities of Egypt lie along those parts of the Nile valley north of Aswan, and nearly all the cultural and historical sites of Ancient Egypt are found along river banks.
Document 3: West Indies: The West Indies or the Caribbean Basin is a region of the North Atlantic Ocean in the Caribbean that includes the island countries and surrounding waters of three major archipelagoes: the Greater Antilles, the Lesser Antilles and the Lucayan Archipelago.
Document 4: European colonisation of Southeast Asia: The spice trade was made possible by the maritime trade route. In 1498, the Portuguese navigator, Vasco da Gama, sailed round the Cape of Good Hope and opened up a sea route from Europe to India. Bringing home samples of exotic oriental products, da Gama greatly increased European interest in the new trade route and the new trade route quickly facilitated the expansion of trade. Eventually, the Dutch wrestled control of it from the Portuguese in the 17th century, and in the 18th century, the British gained control of it from the Dutch. Nevertheless, the spice route greatly increased trading activities, deepened the economic relations between Europe and Southeast Asia and as a result, more European merchants found their way to Southeast Asia.
Document 5: Greater Antilles: The Greater Antilles is a grouping of the larger islands in the Caribbean Sea: Cuba, Hispaniola (containing Haiti and the Dominican Republic), Puerto Rico, Jamaica, and the Cayman Islands.
Document 6: Yangtze: The river originates from several tributaries in the eastern part of the Tibetan Plateau, two of which are commonly referred to as the ``source ''. Traditionally, the Chinese government has recognized the source as the Tuotuo tributary at the base of a glacier lying on the west of Geladandong Mountain in the Tanggula Mountains. This source is found at 33 ° 25 ′ 44'' N 91 ° 10 ′ 57 ''E ﻿ / ﻿ 33.42889 ° N 91.18250 ° E ﻿ / 33.42889; 91.18250 and while not the furthest source of the Yangtze, it is the highest source at 5,342 m (17,526 ft) above sea level. The true source of the Yangtze, hydrologically the longest river distance from the sea, is at Jari Hill at the head of the Dam Qu tributary, approximately 325 km (202 mi) southeast of Geladandong. This source was only discovered in the late 20th century and lies in wetlands at 32 ° 36 ′ 14'' N 94 ° 30 ′ 44 ''E ﻿ / ﻿ 32.60389 ° N 94.51222 ° E ﻿ / 32.60389; 94.51222 and 5,170 m (16,960 ft) above sea level just southeast of Chadan Township in Zadoi County, Yushu Prefecture, Qinghai. As the historical spiritual source of the Yangtze, the Geladandong source is still commonly referred to as the source of the Yangtze since the discovery of the Jari Hill source.
Document 7: Sobat River: The Sobat River is a river of the Greater Upper Nile region in northeastern South Sudan, Africa. It is the most southerly of the great eastern tributaries of the White Nile, before the confluence with the Blue Nile.
Document 8: Walaqa River: The Walaqa River, a tributary of the Blue Nile, is river in the Amhara Region of Ethiopia. Wegde is located to its north. Mida Woremo and Dera are to the south, while Kelala is to the northeast. The Walaqa River may have been the northern boundary of the historical province of Walaqa.
Document 9: Caribbean: The Caribbean (/ ˌkærɪˈbiːən / or / kəˈrɪbiən /, local most common pronunciation / ˈkærɪˌbiːən /) is a region that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Sea and the North Atlantic Ocean) and the surrounding coasts. The region is southeast of the Gulf of Mexico and the North American mainland, east of Central America, and north of South America.
Document 10: Triangular trade: Historically the particular routes were also shaped by the powerful influence of winds and currents during the age of sail. For example, from the main trading nations of Western Europe it was much easier to sail westwards after first going south of 30 N latitude and reaching the so - called ``trade winds ''; thus arriving in the Caribbean rather than going straight west to the North American mainland. Returning from North America, it is easiest to follow the Gulf Stream in a northeasterly direction using the westerlies. A similar triangle to this, called the volta do mar was already being used by the Portuguese, before Christopher Columbus' voyage, to sail to the Canary Islands and the Azores. Columbus simply expanded the triangle outwards, and his route became the main way for Europeans to reach, and return from, the Americas.
Document 11: Muslim world: Advances were made in irrigation and farming, using new technology such as the windmill. Crops such as almonds and citrus fruit were brought to Europe through al-Andalus, and sugar cultivation was gradually adopted by the Europeans. Arab merchants dominated trade in the Indian Ocean until the arrival of the Portuguese in the 16th century. Hormuz was an important center for this trade. There was also a dense network of trade routes in the Mediterranean, along which Muslim countries traded with each other and with European powers such as Venice, Genoa and Catalonia. The Silk Road crossing Central Asia passed through Muslim states between China and Europe.
Document 12: Atlantic slave trade: The Atlantic slave trade or transatlantic slave trade involved the transportation by slave traders of enslaved African people, mainly from Africa to the Americas, and then their sale there. The slave trade used mainly the triangular trade route and its Middle Passage, and existed from the 16th to the 19th centuries. The vast majority of those who were enslaved and transported in the transatlantic slave trade were Africans from central and western Africa, who had been sold by other West Africans to Western European slave traders (with a small number being captured directly by the slave traders in coastal raids), who brought them to the Americas. The South Atlantic and Caribbean economies especially were dependent on the supply of secure labour for the production of commodity crops, making goods and clothing to sell in Europe. This was crucial to those western European countries which, in the late 17th and 18th centuries, were vying with each other to create overseas empires.
Document 13: Caribbean: Situated largely on the Caribbean Plate, the region comprises more than 700 islands, islets, reefs and cays. (See the list.) These islands generally form island arcs that delineate the eastern and northern edges of the Caribbean Sea. The Caribbean islands, consisting of the Greater Antilles on the north and the Lesser Antilles on the south and east (including the Leeward Antilles), are part of the somewhat larger West Indies grouping, which also includes the Lucayan Archipelago (comprising the Bahamas and Turks and Caicos Islands). The Lucayans and, less commonly, Bermuda, are also sometimes considered Caribbean despite the fact that none of these islands border the Caribbean Sea. In a wider sense, the mainland countries, regions, and territories of Belize, the Caribbean region of Colombia, Cozumel, the Yucatán Peninsula, Margarita Island, the Guyanas (Guyana, Suriname, French Guiana, Guayana Region in Venezuela, and Amapá in Brazil), are often included due to their political and cultural ties with the region.
Document 14: Balagas River: Balagas River is a river of northern Ethiopia. A tributary of the Tekezé, its own tributaries include the Balessa and Dorana rivers.
Document 15: Atbarah River: The Atbarah River (; transliterated: Nahr 'Atbarah) in northeast Africa rises in northwest Ethiopia, approximately 50 km north of Lake Tana and 30 km west of Gondar. It flows about 805 km (500 mi) to the Nile in north-central Sudan, joining it at the city of Atbarah (). The river's tributary, the Tekezé (Setit) River, is perhaps the true upper course of the Atbarah, as the Tekezé follows the longer course prior to the confluence of the two rivers (at 14° 10' N, 36° E) in northeastern Sudan. The Atbarah is the last tributary of the Nile before it reaches the Mediterranean.
ground_truth: more than 700
sub_queries: What river does Tekezé River turn into? Answer: Atbarah River
Atbarah River >> continent Answer: Africa
the middle leg of the journey from england to Africa to the americas Answer: the Caribbean
at least how many tropical islands are found in the the Caribbean between florida and venezuela ​ Answer: more than 700