<span>Zookeepers
have a difficulty of keeping koala bears alive because Koala bears are
susceptible to viral infections. There is a virus that is present to Koalas
which is called the Koala retrovirus. Koala retrovirus makes a Koala bear more
susceptible to infections and even cancer. </span>
Answer: thymus
Explanation: T cells adapt in the immune system just like the thymus
Evolution, because it can prove how organisms evolved from past lives.
<span>awake and relaxed with their eyes closed.
The frequency of 10 Hz is right in the middle of the alpha band of 7.5 to 12.5 Hz. Alpha waves are generally detected if the subject is awake and relaxed with their eyes closed. They drop in amplitude when the subject opens their eyes.</span>
Deer are herbivores, their food is composed of plants. Deer receive most of the water they need from the plants they eat.
