Which sentence states a fact?

 - Tomatoes can be red, pink, yellow, purple, white, or black.
 - Red tomatoes taste better when they are cooked.
The first sentence states a fact.
Tomatoes can be red, pink, yellow, purple, white, or black.
It can be proved by checking a website about tomatoes.
The second sentence states an opinion.
Red tomatoes taste better when they are cooked.
Better shows what a person believes, thinks, or feels. Another person might have a different opinion about whether cooked red tomatoes taste better.