Ответ:

hopeless, harmless, worthless, hopeful

Объяснение:

1. Martha thought she was hopeless at math. (without hope)

2. Don’t be afraid of the dog – it’s harmless. (without harm)

3. Pop said the lawnmower was a worthless piece of junk. (without any worth)

4. Pete was hopeful that his project would do well at the Science fair. (full of hope)