Problem: If "I can't cut that tree down with that axe; it is too thick.", is "The axe is too thick." correct?

Answer: no


Problem: If "I was trying to open the lock with the key, but someone had filled the keyhole with chewing gum, and I couldn't get it in.", is "I couldn't get the chewing gum in." correct?

Answer: no


Problem: If "The lawyer asked the witness a question, but he was reluctant to answer it.", is "The witness was reluctant to answer it." correct?

Answer:
yes