Sure, here are the best options for each question:

3. The farmers in my region usually don't grow crops and flowers together.
- **D. together** (The correct phrase should be "crops and flowers together.")

4. It's not always true that living in the city is better than live in the countryside.
- **D. live** (The correct form should be "living in the countryside.")

5. We helped them load the rice onto buffalo-drawn carts and transport them home.
- **D. them** (The correct pronoun should be "it" to refer to the rice.)

6. Will you help me putting up a tent when our school go camping next month?
- **B. putting** (The correct form should be "help me put up a tent.")

7. Their village had no running water, so they collected water to the stream.
- **D. to** (The correct preposition should be "from the stream.")

8. Kelvin was very kind and he acted more responsible than anyone in the class.
- **C. responsible** (The correct form should be "more responsibly.")

9. I lived happily in the farm and there was still more much to explore.
- **D. more much** (The correct phrase should be "much more.")

10. Which activity do you like most, herding a buffalo or riding a horse?
- **No error** (This sentence is correct as it is.)