In the stratosphere ,ozone layer normally has steady concentration of ozone. Comment.

Place the steps tor the formation of the enzyme pepsinogen in correct order

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

The negative impacts of nonnative species generally outweigh the positive impacts