2.12 An Explanation. Self test on structure and language features

Social purpose:

How acid rain is caused
Text structure   Language features
Paragraph 1. Acid 1rain is a major environmental problem in the world, causing fish to die in the earth's 1waters and severely affecting trees and forests, as well as damaging buildings. 1.
Paragraph 2. 3Uncontaminated rain that 4falls from an unpolluted atmosphere is slightly 3acidic. This is 6because carbon dioxide, which is naturally present in the air, 4reacts with water vapour to form 2carbonic acid. The pH 8value of such rain is 5.6. Rainfall with a pH of less than 5.6 is referred to as acid rain. 2. 
Paragraph 3. On average the rain in Sydney, similar to many other large cities, has a pH of 4.3. This 7acidity 6is caused by 2emissions of sulphur and nitrogen oxides which 4form 2sulphurous, sulphuric and nitric acids when they come into contact with water in the air. These 2compounds 5then 4fall to the ground as rain or snow.

3. 
Paragraph 4. Burning 3fossil fuels such as 1coal is a major source of sulphur dioxide, while 3exhaust emissions from cars and trucks 6result in heavy 7concentrations of 2nitrous oxides in the air. 4.

5. 
Paragraph 5. These 2pollutants do not just occur in and around big 1cities. Winds can 4blow them for hundreds of kilometres, so that farmlands and even other countries can 6be affected by acid rain caused by the traffic and 3heavy industry of cities. 6.

7. 

Self test. An Explanation

1. The social purpose of an explanation is to:
a) to describe or classify natural, manufactured and/or social phenomena
b) to present an argument giving a particular point of view
c) to explain how and why phenomena occur in scientific and technical fields
d) to explore various perspectives before coming to an informed decision

II. See if you can indicate the functions of the various stages of the explanation:

2) Paragraph 1: a) general statement of classification
b) summary of arguments presented
c) statement of position
d) identification; statement of phenomenon

3. Paragraphs 2 - 4:
a) explanation sequence
b) background information
c) narration of events with evaluative comments
d) presentation of arguments

4. Paragraph 5:
a) summary of events
b) optional concluding statement
c) coda
d) re-orientation

III. See if you can answer the questions about the typical language features for explanations:
5. These nouns, 1rain, waters, cities, coal are:
a) specific
b) abstract
c) proper
d) general

6. These words, 2carbonic acid, sulphurous, sulphuric and nitric acids, compounds, nitrous oxides, pollutants, are:
a) compound nouns
b) technical terms
c) Examples of emotive language
d) attributive adjectives

7. These adjectives, 3uncontaminated, acidic, fossil, exhaust, are:
a) quantity
b) factual and classifying
c) opinion d) comparing and contrasting

8. The verbs, 4falls, reacts, form, blow, are:
a) relating
b) saying
c) sensing
d) action

9. This word 5then is:
a) a causal connective
b) preposition
c) a time connective
d) a referring word

10. These words, 6because, is caused, result, be affected are:
a) adverbials showing the location of events
b) sensing verbs
c) prepositional phrases
d) causal connectives, conjunctions and verbs

11. This form is also commonly found in explanations. The words, 6is caused, be affected are:
a) verbs in the passive voice
b) verbs in the active voice
c) modals
d) auxiliaries

12. These words are also typical language features of explanations. The words, 7acidity (paragraph 3), concentrations (paragraph 4), are
a) concrete nouns
b) adjectivals giving more information about the nouns
c) nominalisations to name abstract phenomena
d) subjective nouns to persuade the reader to adopt a particular point of view

13. 8value in paragraph 2 is another type of word often found in explanations. It is:
a) a verb
b) a proper noun
c) an adverbial
d) an abstract noun


Score = /13
Correct answers:

Explanations to Self-Test