Meaning: 'Helps to improve' means to assist in making something better or enhancing its quality.

Wrong options:

• helps improving: This option is incorrect because 'helps improving' is not a standard grammatical structure; 'improving' is a gerund and does not fit after 'helps.'
• help improve: This option is incorrect as 'help' is in the base form and does not agree with the singular subject 'equipment.'
• help improved: This option is incorrect because 'help improved' uses the past participle 'improved,' which does not fit the context of ongoing assistance.

Correct answer: levels

Explanation: The word 'levels' is appropriate as it refers to the different degrees or amounts of poverty, fitting grammatically as a plural noun that aligns with 'reducing' and contextually as it describes the various extents of poverty.

Meaning: 'Levels' refers to the different stages or degrees of something, in this case, poverty.

Wrong options:

• ranks: This option is incorrect because 'ranks' typically refers to a position in a hierarchy and does not convey the idea of varying degrees of poverty.
• stages: This option is incorrect as 'stages' implies a sequence or phases, which does not fit the context of measuring poverty.
• degrees: This option is incorrect because while 'degrees' can refer to levels, it is less commonly used in this context compared to 'levels' when discussing poverty.

Correct answer: since

Explanation: The word 'since' is the correct choice as it indicates a starting point in time (the year 2000) and is used with the present perfect tense 'has risen,' fitting grammatically and contextually to show the duration of the increase in coal consumption.

Meaning: 'Since' means from a specific time in the past until now, indicating the beginning of the increase in coal consumption.

Wrong options:

• for: This option is incorrect because 'for' indicates a duration of time but does not specify a starting point, which is necessary in this context.
• in: This option is incorrect as 'in' would suggest a specific time period rather than indicating the starting point of an ongoing action.
• at: This option is incorrect because 'at' is used for specific points in time and does not convey the ongoing nature of the increase since 2000.

Correct answer: means

Explanation: The word 'means' is suitable as it refers to a method or way of achieving something, fitting grammatically as a noun that describes coal's role in power production.

Meaning: 'Means' refers to a method or resource used to achieve a goal, in this case, producing power.

Wrong options:

• factor: This option is incorrect because 'factor' implies a contributing element but does not convey the idea of a method or means of production as clearly as 'means.'
• aspect: This option is incorrect as 'aspect' refers to a particular part or feature, which does not fit the context of producing power.
• course: This option is incorrect because 'course' typically refers to a direction or path, which does not align with the context of production.

Correct answer: figure

Explanation: The word 'figure' is appropriate as it refers to a numerical amount or statistic, fitting grammatically as a noun that describes the quantity of electricity produced.

Meaning: 'Figure' refers to a numerical representation or amount, in this case, the percentage of global electricity produced by coal.

Wrong options:

• total: This option is incorrect because 'total' refers to the whole amount but does not convey the idea of a specific statistic as clearly as 'figure.'
• sum: This option is incorrect as 'sum' implies the result of addition, which does not fit the context of a percentage of electricity production.
• volume: This option is incorrect because 'volume' typically refers to the amount of space occupied, which does not align with the context of electricity production.