1Researchers have determined that the melting of polar ice is accelerating. 2While it is normal for some of the ice to melt in the spring and summer, measurements indicate that melting is now occurring earlier in the spring. 3The ice is re-freezing later in the fall and winter, as well. 4Scientists believe water temperatures have increased due to global warming. 5Sea ice is the portion of polar ice that floats in the ocean (instead of being on land). 6In the Northern Hemisphere, sea ice has been melting so quickly that many scientists think there will be no Arctic sea ice in the summers by the later part of this century. 7Ocean currents are "conveyor belts" of water that move far below the surface of the world's oceans. 8These bands of water move cooler water from the polar regions toward the equator, and they move warmer water back toward the poles. 9Scientists believe this helps to control the Earth's climate. 10Polar ice and ocean currents are directly connected. 11As the polar ice melts, it changes the density of the sea water in the region. 12This reduces the ability of the sea water to sink, which is necessary for the ocean currents to continue to flow. 13Because of the rapid melting of sea ice, many researchers are concerned that the ocean currents could slow or even stop working entirely. 12. For each sentence number, identify the topic or topics MOST directly mentioned in THAT sentence. You may or may not need to select more than one button in a row. (5 points) polar ice ocean temperature ocean currents sentence 1 sentence 4 sentence 5 sentence 7 sentence 10
sentence 1: polar ice
sentence 4: ocean temperature
sentence 5: polar ice
sentence 7: ocean currents
sentence 10: polar ice