I NEED HELP ASAP 25 POINTS Slash and Burn & Deforestation

1.William Gorgas is given credit for getting rid of Yellow Fever. How did he do it?

a. Developed a New Medicine
b. Immunization
c. Killed all Mosquitoes

2. Why was slash and burn agriculture more sustainable in the past?

a. It provides nutrients to the soil.
b. It was always sustainable
c. They only cultivated enough land to feed their families.
d. They have always been using it.

3.What is another negative impact of slash and burn

a. the land would be wasted for years
b. the land wouldn't ever grow back