Answer:A weak immune system
Explanation:
When people get older their immune system becomes weak including the function of the T cells which are cells responsible for fighting infections.
This means it becomes hard to recover from a flue when someone get sick and they are always prone to sickness since their immune system no longer has the power to fight infections.
D hope this helps---------
Answer:
An earthquake is when the earth quakes at it's core.
One Difficulty that early researchers encountered in identifying the good judge of personality was that a good judge in one content was not always a good judge in other contexts. hope this helps..:)
