Which trophic level is the most important for the ecosystem and why​

Which best describes how the common cold spreads in the human body? a bacteria burst out of normal cells killing them b viruses replicate inside respiratory cells c bacteria inject dna into normal cells d viruses insert dna into bacteria

Aflashlight battery is an example of a) potential energy b) kinetic energy c) thermal energy d) solar energy

Aperson with age is more likely to catch diseases that healthy people usually don’t catch. what are these infections called?