1. I have heard this radio program several times. Я слышал эту радиопрограмма несколько раз.

2. She bought a dress in Paris.

Ответы:

1. I have not heard this radio program several times.

2. She has not buy a dress in Paris

3. They have not seen that exhibition

4. We have not finished exercise some minutes ago

5. Jack has not climbed a very tall tree.