The Threat Posed by Some Synthetic Chemicals Is Difficult to Assess

Q25: Heavy metals accumulate in organisms,increasing in their

Q26: When human activities alter natural chemical cycles

Q27: Groundwater pollution can be reduced by introduction

Q28: Lead,mercury and plutonium are these that have

Q29: Use of microorganisms to break down toxic

Q31: Eutrophication caused by excess runoff of nitrate

Q32: The pump-and-treat method is<br>A) The surface treatment

Q33: Water containing an abundance of nutrients,which encourages

Q34: Groundwater pollution<br>A) Comes only from non-point pollution

Q35: Mercury<br>A) Is most toxic to humans in