8. He _______ so many interesting facts about nature if he didn't read much. (not / to know)

He **wouldn't know** so many interesting facts about nature if he didn't read much. **Объяснение:** Это условное предложение второго типа (Second Conditional). В части с 'if' используется Past Simple (didn't read), а в основной части предложения – would not (wouldn't) + инфинитив (know).