During the recession of 2007-2009, despite falling income levels, the fast-food chain Subway experienced increased sales. The increase in demand for Subway sandwiches despite the decline in income indicates that Subway sandwiches are considered .

inferior goods

Explanation:

During the recession of 2007-2009, despite falling income levels, the fast-food chain Subway experienced increased sales. The increase in demand for Subway sandwiches despite the decline in income indicates that Subway sandwiches are considered inferior goods.  Inferior goods are defined as goods whose demands increases with a decrease in consumers income and whose demand decreases with an increase consumers income. If the consumer has higher level of income, they would consume inferior goods lesser.

using the scientific method.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.