Vocabulary and Synonyms

Renowned means known or talked about by many people, usually for something positive. Celebrated is a close synonym, meaning famous and well-respected. Infamous and notorious mean famous for bad reasons, which is the opposite of the positive connotation of renowned.

The phrase "when trying" is a reduced adverb clause (short for "when they are trying") that correctly modifies the action of reversing letters. "When tried" is passive and does not make sense here, while "if they tried" uses an incorrect tense sequence.

The word 'considerable' is used to describe something that is notably large in size, amount, or extent, which means it is significant or important. Options like 'possible' or 'understandable' do not capture this sense of scale or importance.

The word 'internal' relates to the inside of something, so 'happening inside' is the most accurate definition. The other options describe importance, communication, or relevance, which do not mean internal.

The word 'annual' means occurring once every year, making 'yearly' the correct definition. The other choices describe frequency, visibility, or structure, which are incorrect.

The word 'labor' refers to practical work, especially hard physical work. The other options refer to emotions, transitions, or feelings, which do not define labor.

Being 'aware' means having knowledge or perception of a situation or fact, which is best described as 'knowing something is happening.' The other options describe capability, authenticity, or fear.

The word 'prior' means existing or coming before in time, order, or importance, so 'happening before' is the correct definition. The other options describe power, truth, or origin.

A 'site' is an area of ground on which a town, building, or monument is constructed, or more generally, a place or location. The other options describe communication, perception, or physical materials.

The word 'stable' means firmly established and not likely to change, fail, or move. This is directly captured by 'not changing, not moving.'

The word 'precise' means marked by accuracy and detail, which is synonymous with 'exact.' The other options describe importance, truth, or size.

To concentrate means to direct all of your attention, effort, or focus onto a single activity or subject. While it can also mean to gather in high density, focusing on something is its most common everyday definition.

To vary means to differ or be different from something else in size, amount, or degree. While it can involve change, its core meaning is to exhibit differences or diversity.

To expose means to reveal or show something that was previously hidden, protected, or secret. This can refer to physical objects being uncovered or secrets being brought to light.

To sustain something means to strengthen or support it physically or mentally, or to cause it to continue for a period of time. Therefore, "continue" is the closest definition among the choices. The other options describe joining, identifying, or polluting, which are unrelated to sustaining.