Urban areas tend to be warmer than the rural areas that surround them. this is mainly caused by how the materials that humans use for building, such as concrete, absorb and radiate energy from the sun. this is known as the "heat island" effect. which of the following can be altered by the heat island effect? a. local weather patterns b. local volcanic activity c. the ocean tides d. the movement of crustal plates

Look at the figure above. which atmospheric layer has around 80 percent of the mass of the earth's atmosphere? (hint: it's where the clouds seen on earth are formed.) a. exosphere b. troposphere c. stratosphere d. thermosphere

Tlymphocytes mature in the? a. thyroid gland. b. bone marrow. c. spleen. d. thymus.

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes