Question

1. select your class hour. mark only one oval. 1st 2nd 3rd 5th 6th 4. 1. an atmospheric gas that increases when fossil fuels are burned mark only one oval. ecological succession secondary succession carbon dioxide algal bloom climax community old - field succession 5. 2. evidence of excessive fertilizer use mark only one oval. ecological succession secondary succession carbon dioxide algal bloom climax community old - field succession

Explanation:

• For question 4, when fossil - fuels are burned, carbon dioxide is released into the atmosphere, increasing its concentration.
• For question 5, excessive fertilizer use can lead to eutrophication, which often results in algal blooms.

Answer:

1. carbon dioxide
2. algal bloom