1.Having failed a number of times, he is learning how to think ________. A. science B. scientific C. scientifically D. scientifical 2.Carbon dioxide is released through _________ processes such as respiration and volcano eruptions and through _________ activities such as deforestation, land use changes, and burning fossil fuels. A. man–made / ordinary B. human / natural C. ordinary / man –made D. natural / human 3. A strong greenhouse effect will warm the oceans and partially melt glaciers, increasing _________. A. sea level B. temperature C. sea water D. pollution 4. Her classmates admire her so much because she has a clear _________ mind. A. analysis B. analytical C. analytics D. analyze 5. ________ means an illness that can be passed from one person to another, especially through the air people breathe. A. infectious disease B. heat-related illness C. headache D. stomach ache 6. A large amount of carbon dioxide ________ are released into the atmosphere by burning fossil fuels. A. gases B. emissions C. effects D. levels 7. I believe that the only way for us to reduce global warming is to cut down ________ energy use. A. on B. to C. at D. in 8. The alarming rate of deforestation results in damage ________ the quality of the land. A. to B. in C. at D. for 9. Deforestation is one of the biggest environment threats to the ________ in the world. A. infectious diseases B. ecological balance C. carbon footprint D. greenhouse gases 10. _____________ is a stable ecosystem in which a large number of species live together A. Greenhouse gas B. Climate change C. Global warming D. Ecological balance