IELTS Writing Test 13 "The chart below shows the average daily minimum and maximum levels of two air pollutants in four big cities in 2000. Summarise the information by selecting and reporting the main features, and make comparisons where relevant". The chart shows the average daily minimum and maximum levels of two air pollutants (sulphur dioxide and dinitrous oxide) in four big cities in 2000 (LA, Calcutta, Beijing and Ciudad de Mexico). We can watch that the maximum levels of SO2 and N20 in Ciudad de México are higher than the other cities with values of 200 and 207 respectively. These values are follow by Beijing with a value of 130. If we check the minimum levels, Ciudad de Mexico has the higher value in the minimum level of SO2 and N20 as well, with values of 80 and 13 respectively. Therefore, it had critical values related to air pollutants during 2000. On the other hand, Los Angeles had the lower value of SO2 but the maximum level of dinitrous oxide is higher than Calcutta and Beijing. Calcutta had the higher value of this chemical than Los Angeles, however, there was a estable value of this two air pollutants during this year.