Questions

If some action has started in the past and is still continuing, then present perfect continuous tense should be used instead of present continuous tense. So, the phrase ‘is working’ needs to be replaced with ‘has been working’ to make the sentence contextually correct. Thus, the correct formation would be, ‘Ramesh has been working in this factory for the past three months’.

Insolent means ill-manneredSullen means moodyAffable means good-naturedwhich is nearly opposite to InsolentDetermined means purposeful

The modal ‘Could’ is used to express possibility. It is simply used to state one or more things that are possible or were possible in the past. In this statement, ‘to have achieved’ needs to be replaced with ‘for achieving’ to make the sentence correct. Thus, the correct sentence would be, ‘When I finished writing the letter, I could not help admiring myself for achieving the impossible’.