雅思阅读话题词汇-31-40

31.convert

phrase for: convert to/into

synonym:change,transform

eg1: The high temperatures in the toughening process convert all the crystals to dense, compact alpha form, but the subsequent cooling is so rapid that the crystals don't have time to change back to the beta phase

eg2:The original house was converted into a residential college

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

32.crack

pahrase for:crack up; crack down on

eg1: If the shell is slightly cracked during boiling, the white material will bubble out and set like a tiny mountain chain over the crack-like an archipelago of valcanic islands such as the Hawaiian Islands

eg2:Viscous lava, accompanied by burning clouds of ash and gas,welled out of the volcano from cracks in its flanks

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

33.crater

eg1:What comes out of volcanic craters is mostly gas. More than 90% of this gas is water vapour from the deep earth ; enough to explain, over 3500 million years, the water in the oceans

eg2: The slightly cooler lava following it begins to flow over the lip of the crater

eg3: After a volcano erupted, lava domes have formed inside the new crater, and have periodically burst

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

34.crust

eg:Look at maps of volcanoes, earthquakes and island chains and you can see the rough outlines of tectonic plates- the  plates which make up the earth's crust and mantle

35.culminate

synaton:end;terminate;top

eg: By 1400, the weather had become more unpredictable,with sudden shrifts and lower temperatures that culminated in the cold decades of the late sixteen century

------------------------------------------------------------------------------------------------------------------------------------------------------------------------

36. cumulative

eg: The condition appears to result from the cumulative affect of a number of factors,with atmospheric pollutants the principal culprits

-------------------------------------------------------------------------------------------------------------------------------------------------------

37.current

phrase for: air currents; current affairs;ocean current;alternating current; the current situation

eg1:One set of candidates are known as paraelectric materials.These act like batteries when they undergo a temperature chang:attach electrodes to them and they generate a current.

eg2: He is recommending the immediate introduction of a 'Green Food Standard',which would push the market towards more sustainable environmental practices than the current norm

eg3: I should like to open a current account 

-------------------------------------------------------------------------------------------------------------------------------------------------------

38. delta

phrase for: the Nile delta; fan delta; bay delta

eg1:Every year flooding brought in new,nutrient-rich soil to the delta region, replacing the soil washed away by the sea,and supplying fertilizers for Egypt's richest food-growing area

eg2: The Nile divides at its mouth and forms a delta.

-------------------------------------------------------------------------------------------------------------------------------------------------------

39. depletion

eg1:A study found that car transport is seven times as costly as rail travel in terms of the external social costs for it entails such as congestion, accidents,pollution,loss of cropland and natural habitats,depletion of oil resources, and so on

-------------------------------------------------------------------------------------------------------------------------------------------------------

40.debris:

eg1;Many ants are small and forage primarily in the layer of leaves and other debris on the ground

eg2: As the sliding ice and snow melted, it touched off devastating torrents of mud and debris, which destroyed all life in their path