Past Simple and Present Perfect. Present Perfect Continuous
10.1 Read the text about climate change. Choose the correct form, A or B, to complete the sentence: At the moment, scientists agree that the world's climate 1) B warmer over the past 50 years, but they disagree about the causes. Some believe that human activities 2) ___ climate change. They argue that for 1,000 or 2,000 years before 1850, when records3) ___, the temperature was more or less stable. Short warm or cold periods 4) ___ during that time, but the climate always5) ___ to the same level. However, since the Industrial Revolution, human beings 6) ___ more and more fossil fuels, such as coal and oil. In 1800 the atmosphere 7) ___ around 280 parts per million of carbon dioxide (CO2). Since then there 8) ___ an increase of about 3 l%. This extra carbon dioxide 9) ___ the world's temperature because of the greenhouse effect. Other scientists disagree that human activities over the past 50 years 10) ___ global warming. They point out that volcanoes and other In 1999, 156 countries13) ___ the Kyoto protocol, part of a United Nations agreement on climate change, which14) ___ into force in 2005.They 15) ___ to reduce their emissions of CO2 and other greenhouse gases, although so far, some countries, such as the USA and 1. A became B 2. A caused B have caused 3. A began B have begun 4. A occurred B have occurred 5. A returned B has returned 6. A burned B have burned 7. A contained B has contained 8. A was B has been 9. A raised B has raised 10. A caused B have caused 11. A always released B have always released 12. A contributed B has contributed 13. A signed B have signed 14. A came B has come 15. A agreed B have agreed 16. A did not take B have not taken
Present Perfect Continuous Use 1) actions started in the past and continuing up to the present He 's been writing a letter for two hours. (He started two hours ago and he's still writing it) 2) past actions of certain duration having visible results or effects in the present She 's been crying. (Her eyes are red.) 3) actions expressing anger, irritation, annoyance, explanation or criticism Who has been using my toothbrush? (annoyance) 4) emphasis on duration (usually with for, since or how long) She 's been calling on clients since this morning. Time expressions:how long, for, since
Note: live, feel and work can be used either in the Present Perfect or the Present Perfect Cont. with no difference in meaning. I’ve been living / I’ve livedin Rome for a year.
11.1 Complete the sentence using the verb in brackets in the present perfect continuous form:
1. I’m sorry to keep you waiting. I hope you (not wait) __________ long. 2. There you are! We (look for) __________ you all morning! 3. I feel really tired. I (study) __________ hard lately. 4. Anna has got a really good suntan. She (go) __________ to the beach a lot. 5. Tom needs cheering up. He (have) __________ a lot of problems lately. 6. I haven’t seen you for ages. What (you / do) __________? 7. I (work) __________ here for the past three years, and I really like it. 8. Sam and Chris (paint) __________ their room, and their clothes are covered in paint! 11.2* Underline the correct form:
A. Scientists 1) have recently identified / have been identifying a new species of animal in the rainforest of Borneo. They2) have been searching / searched for this creature for several years, after reports from local villagers, and say it is a type of lemur. B. Archaeologists in Guatemala 3) have found / have been finding a Mayan wall painting which they think is more than 2,000 years old. Archaeologist William Saturno 4) explored / has been exploring the site since 2002. C. Scientists using the Hubble Space Telescope think they5) found / have found two new moons circling the planet Pluto. Astronomers6) have been looking / looked closely at Pluto since 1978 when they 7) spotted / have spotted its first moon. The telescope8) worked / has been working for fifteen years, and 9) has been producing / has produced more than 700,000 images of the universe. D. Australian scientists10) have been discovering / have discovered a new coral reef over 60 km long in the Gulf of Carpentaria by using satellites to spot the reefs in deep water. Recently divers11) have managed / have been managing to reach the reefs and take photographs.
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