Because the birds that fly overseas carry different flu viruses every year.
Answer:
Scientific Method.
Explanation:
A scientific method is basically a method or a process when you conduct an experiment. Normally, the process goes like this:
1. You make like a question or something that you want to investigate, it's like the aim of the experiment.
2. You make an experiment and a hypothesis. A hypothesis is basically a guess on how the results of the experiment would turn out. You don't have to be correct for the hypothesis since there is no right or wrong answer.
3. Conduct the experiment. I don't think this needs a detailed explanation since experiments vary from one another.
4. Collect results. The data you collect come in different ways based on your experiment, but it is crucial you get data so that you can answer your question in 1.
5. Make inferences. You can't directly get a conclusion or answer from the results, so inferences are needed.
6. Craft a conclusion or answer. This is the final step when conducting an experiment and the part where you have the answer you needed when you conducted the experiment :)
H3PO4 has molecular weight of approximately 98 grams per
mole. 4.50 M is equal to 4.50 mole per 1000 mL solution of H3PO4. 255 mL times
4.50 mol /1000 mL times 98 g/mol is equal to 112.455 grams. Note that I
automatically equate 1 Liter to 1000 mL since the given volume is in mL for
easier computation.