Do u still need help I know how to do that
The flu vaccine changes every year. The flu vaccine is based on a predicted strain that is anticipated to be the most infectious that year. Thats why people who sometimes get the vaccination still get the flu, they don't have the antibodies for the strain they were infected with. Strains for viral disease don't change very much and usually the vaccination for them cover them well.
The answer is c. Vibrates on one spot
Answer: Ice cores.
Explanation: Ice cores are commonly studied by scientists to find out what the climate was like decades and centuries ago.