Bacterial and viral infections of the brain are rare because the prevents most viruses, proteins, and bacteria from entering the cerebrospinal fluid.

blood-brain barrier

Explanation:

The brain is well protected against microbial invasion by cellular barriers, such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). In addition, cells within the central nervous system (CNS) are capable of producing an immune response against invading pathogens.

the correct answer is(the type of energy described here is potential energy.)

explanation: now if the person holding the bow and arrow has now let go. the arrow shoots forward toward its target. the   type of energy then becomes

the answer is admiramos

the rule for verbs is whoever you are referring to (in this case 'nosotros'), you need to change the ending of the word.

nosotros - amos

yo - o

tu - as

el, ella, usted - a

ellos, ellas, ustedes - an

(examples: nosotros bailamos (instead of bailar) or yo hablo (instead of habla)