What happens during the krebs cycle

Are the earth's ocean floor and continents the same age geologically? why or why not?

Svetlana and her mother are very similar. both have blonde hair, a love of scrapbooking, blue eyes, and a thin nose. which statement  most likely  describes svetlana’s traits? svetlana inherited her love of scrapbooking from her mother, but her blue eyes come from her environment.svetlana inherited her blue eyes from her mother, but her love of scrapbooking comes from her environment.svetlana inherited her thin nose from her mother, but her blonde hair comes from her environment.svetlana inherited her blonde hair from her mother, but her thin nose comes from her environment.

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?