A. 1.34. x 1024 molecules H2O
2. A
3. D (got cut off but the others don’t seem right)
4. D
Hopefully these are correct
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.
Answer:
Animals and plants need nitrogen to build amino acids in proteins, which are the building blocks of life. Unlike oxygen, nitrogen cannot be absorbed directly from the air by animals and plants.
Explanation: