Identify two variables that you would control if you were carrying out an investigation into the effects of peroxidase concentration on the breakdown of H2O2. State how you could control each of these variables.

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels