The region produces over 50% of the country's wheat. (production) - Here, "produces" is the verb that best reflects the act of generating or providing the wheat.

He has worked as a conservationist in that organization for 12 years. (conserve) - "Conservationist" refers to someone who protects and manages natural resources, which aligns with the idea of conserving something.

The truth of this statement has been verified in Chapter 1. (effect) - "Effect" as a noun often refers to a result or consequence. "Verified" means to confirm something is true, which aligns better with the context.

My hometown is really a romantic and picturesque village. (picture que) - "Picturesque" means like a beautiful painting, which captures the essence of a charming village.

It is pure entertainment and there's nothing wrong with that. (entertain) - "Entertainment" refers to something that provides amusement or enjoyment, which aligns with the idea of something purely for fun.