You arrive back in the United States after a visit to a foreign country located on another continent. The customs agent stops the person in front of you and confiscates the fruit basket this person is bringing home. Being the knowledgeable person you are, you calmly explain to your enraged fellow traveler that the reason for the detainment is that the fruit basket may be
◦ carrying endangered fruit.
◦ contaminated with chemicals that will damage the ozone layer above North America.
◦ contaminated with sufficient DDT to cause serious harm to anyone who eats the fruit.
◦ carrying an exotic species that could damage North American ecosystems.