Answer:
A. keeps you healthy
Explanation:
The immune system protects your body from outside "invaders," such as bacteria, viruses, fungi, and toxins.
The youngest would be the ones at the top and the oldest would be at the bottom. the oldest is B and the ones around it, as they get bigger get younger. hope this helps :)
(I wrote to you more than three types)
There are seven known types of human coronavirus. Four common types (KHUI, OC43, NL63,229E) cause mild to moderate respiratory infection, such as the common cold. There are two types, severe acute respiratory syndrome (SARS-COV) and Middle East respiratory virus syndrome (MERS-COV), that can cause acute respiratory infections. Type VII (nCOV-2019) is the newly discovered novel coronavirus in China.
Answer:
CU, in the periodic table. Stomic number 29.
