A genetic engineer wants to join the following DNA fragments. Which tool should the engineer use?
O reverse transcriptase
O DNA ligase
O gel electrophoresis
O restriction endonuclease

To join the DNA fragments the genetic engineer must use DNA ligase.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

feral cats are estimated to eat tens of millions of native animals each night in australia