Ambiguity w języku angielskim

Temat przeniesiony do archwium.
Please help me with my homework. Please provide two meanings of each sentence.

1. The work should be completed by the end of the month.
2. She burned his last letter, in which he had proposed to her, so that no one could ever discover the truth.
3. He might have realized that you were pulling his legs.
4. She left me to get on with her work.
5. After the marathon race the runners were very tired, if not exhausted.
6. The ambassador did not leave London to take up an appointment in Africa.
pomoc jest wtedy, gdy jest wkład własny

1 ja bym próbował różnie interpretować 'by the end of the month'