Which example emphasises: the length of an action, the results of an action, an action which started in the past and has continued to the present, an action that took place some time in the past, a repeated action up to the present?

The question asks to identify which example best describes the characteristics of the Present Perfect Continuous tense. Let's analyze the options:

1. 'I've known her since primary school.' - This is Present Perfect, emphasizing a state that started in the past and continues to the present, but it's a state, not an action in progress.
2. 'We've already seen that film.' - This is Present Perfect, emphasizing the result (having seen the film) and completion.
3. 'I've been reading for two hours.' - This is Present Perfect Continuous, emphasizing the duration and the ongoing nature of the action (reading) up to the present.
4. 'She has broken her arm. She has a cast.' - This is Present Perfect, emphasizing the result (broken arm and cast).
5. 'My uncle has been going to that café for 20 years.' - This is Present Perfect Continuous, emphasizing the duration and the repeated action (going to the café) up to the present.

Based on the definition provided in the question ('an action that took place some time in the past, a repeated action up to the present?'), examples 3 and 5 fit best. However, the question asks for *which example* emphasizes the length of an action and a repeated action up to the present. Example 3 emphasizes the duration of an action. Example 5 emphasizes a repeated action over a long period. The question's phrasing is a bit ambiguous, but it seems to be looking for the continuous aspect. The phrase 'length of an action' and 'repeated action up to the present' strongly suggests the Present Perfect Continuous. Both 3 and 5 fit this. If we have to choose one that best fits 'length of an action' and 'repeated action up to the present', example 5 is a strong candidate for repeated action, and example 3 for length of action. The question asks for 'the length of an action' AND 'a repeated action up to the present'. Example 5 fits both 'length' (20 years) and 'repeated action' (going to that cafe). Example 3 fits 'length' (two hours) but not necessarily 'repeated action'. Therefore, example 5 is the most comprehensive fit for the description provided in the question.