Which inventions had the greatest impact on trade in china during the middle ages?

The model of human settlement suggests that uthe model of human settlement suggests that urban growth is patterned around transportation networks such as railroads and highways. a. burgess b. hoyt c. sauer d. von thunenrban growth is patterned around transportation networks

What are the answers for the following questions?

Dubai is challenged by all of the following environmental factors except a. a warm and dry climate b. a lack of annual rainfall c. scarce freshwater resources d. a lack of valuable natural resources