Money you earn by working, investing, or producing goods is best described as income. Income is the broad term for money received over a period from any source—wages and salaries, profits from a business, interest or dividends from investments, rents, and more. It captures all the ways someone can bring money in, not just one specific source. Earnings is similar but more specific, often used to refer to money earned from work or from investments, sometimes within a particular context. Salary denotes a fixed regular payment from an employer, and revenue refers to the total income a business collects from selling goods or services, not an individual's earnings. Example: "Her income comes from a salary plus investment dividends."

Indicating that a value is not exact is done with approximate language. When numbers are rounded or measurements have some error, you use “approximately” to show the figure is near another value but not claimed precisely. This helps readers understand the level of precision. The other options imply certainty or precision: “certainly,” “exactly,” and “definitively” all suggest there is no deviation or doubt. So the term that best communicates an approximate value is the one that signals nearness without exactness.

Planning length to reliably meet the 150-word minimum while delivering a clear overview and data points is essential. The recommended target is about 180 words. This provides a comfortable buffer above the minimum so you won’t risk writing under 150 if your counting slips, while still staying concise and focused. With roughly 180 words you can include a brief overview of overall trends and several specific data points or comparisons, all in a coherent four-to-five sentence structure that IELTS examiners expect. If you aim too close to 150 words, there’s less room for nuance and you might omit important details; if you try to write much more than 180, there’s a higher chance of wandering or including irrelevant information. So, a target around 180 words helps you demonstrate the ability to summarize and compare data effectively within the typical length guidelines.

This item tests how to refer back to a time period that was already stated in the text. The phrase that signals this exact, previously mentioned period is the period in question. It explicitly points to the specific time frame under discussion, using a standard, unambiguous expression that keeps the reference clear for the reader. The other options are more general or imply a different kind of reference: a broad time frame not tied to what was described earlier, a focus that's more about emphasis than a specific prior mention, or a label for something being reviewed rather than the exact period previously described. So the period in question is the best choice because it directly and precisely ties the reference back to the earlier stated time.