根据以下材料,回答1-20题。
Caravanserais were roadside inns that were built along the Silk Road in areas such as China, North Africa and the Middle East. They were typically 1 outside the walls of a city or village and were usually funded by local governments of 2 .
The word ‘caravanserai’ is a 3 of the Persian words ‘karvan’, which means a group of travellers or a caravan, and ‘saray’, a palace or enclosed building. The term caravan was used to 4 groups of people who travelled together across the ancient network for safety reasons, 5 merchants, travellers or pilgrims.
From the 10th century onwards, as merchant and travel routes become more developed, the 6 of the caravanserais increased and they served as a safe place for people to rest at night. Travellers on the Silk Road 7 possibility of being attacked by thieves or being 8 to extreme weather conditions. For this reason, caravanserais were strategically placed 9 they could be reached in a day’s travel time.
Caravanserais served as an informal 10 point for the various people who travelled the Silk Road. 11 , these structures became important centres for cultural 12 and interaction, with travellers sharing their cultures, ideas and beliefs, 13 talking knowledge with them, greatly 14 the development of several civilisations.
Caravanserais were also an important marketplace for commodities and 15 in the trade of goods along the Silk Road. 16 , it was frequently the first stop merchants looking to sell their wares and 17 supplies for their own journeys. It is 18 that around 120,000 to 15,000 caravanserais were built along the Silk Road, 19 only about 3,000 are known to remain today, many of which are in 20 .