Why does a person have to get a flu shot every year? Why isn't one flu shot for life enough?

1. label high-pressure areas with the letter h. 2. label low-pressure areas with the letter l. 3. over which area(s) would you expect to see rain or snow? 4. over which area(s) would you expect to see clear skies? 5. draw arrows around the h on the map to show the wind direction. 6. draw arrows around the l on the map to show the wind direction. 7. imagine that you live in maine. currently there is a high-pressure area over maine. if a low-pressure area moves in, how will the direction of the wind change? 5. draw arrows around the h on the map to show the wind direction. 6. draw arrows around the l on the map to show the wind direction. 7. imagine that you live in maine. currently there is a high-pressure area over maine. if a low-pressure area moves in, how will the direction of the wind change? 8. imagine that you live in colorado. currently there is a low-pressure area over colorado. if a high-pressure area moves in, how will the direction of the wind change? 9. according to the map, where would the strongest winds be expected? (refer to the lesson if needed.)

What are the four basic classes of organic molecules how do they differ structurally and functionally

This is a biological reaction due to a stimulus. i need this quickly !