Fuel oil pollution control and additional maintenance required after burning it often outweigh the low cost of the fuel. Burning fuel oil, particularly residual fuel oil, produces uniformly higher carbon dioxide emissions than natural gas. Heavy fuel oils continue to be used in the boiler "lighting up" facility in many coal-fired power plants. This use is approximately analogous to using kindling to start a fire. Without performing this act it is difficult to begin the large-scale combustion process. The chief drawback to residual fuel oil is its high initial viscosity, particularly in the case of No. 6 oil, which requires a correctly
Interlanguage fossilization to learning second language, and the relationship of fossilization to the learner's communicative needs. Arguments have emerged regarding adult learners' general lack of empathy with target language native speakers and culture. According to Guiora et al., adults do not have the motivation to change their accent and to acquire native-like pronunciation. Unlike children, who are generally more open to target language culture, adults have more rigid language ego boundaries. Thus, adults may be inclined to establishing their pre-existing cultural and ethnic identity, and this they do by maintaining their stereotypical accent. Notwithstanding this, there is a lack of needed research,