Vaccination has proven to be a highly effective weapon against certain diseases. –, which at its peak in the 1940s and 1950s infected – in the United States each year, has been – eradicated worldwide through vaccination. Newly developed vaccines against diseases such as – hold great promise as a public health tool in Africa.

Both in the Americas and worldwide, malaria is less of a problem than it once was. Place in chronological order the steps that were taken to fight it.

Explanation:

to increase speed you need to decrease frictiona dn drag hense why sprinters wear tight track suits to keep tight against there skin to keep away from wind and decrease the amount of drag you are carrying.a swimmer will wear the tightest swim suit they can possibly fit into (i was a size 28 swim suit at meets i wore a   size 23) why? because the tighter your clothing is the less drag and negative force you have. the heavier the clothe the slower and more wind gets caught. cotton tends to hold onto alot of sweat and water making it slower then say a track suit (no idea what they are made of but they are really comfy around your answer )

answer; i believe that the correct answer is (essential amino acids);