【Whenyoubuycookingoilinthesupermarket，youmaynoticethatsomebrandsarelabeledas"GM（geneticallymodified转基因）-free"．So，whatisgeneticmodification？AreGMfoodssafe？Thesequestionshavebeenputbackintothe】

　　When you buy cooking oil in the supermarket，you may notice that some brands are labeled as"GM （genetically modified 转基因）-free"．So，what is genetic modification？Are GM foods safe？

　　These questions have been put back into the public attention recently．On Nov 19，the Food and Drug Administration （FDA） in the US announced that it had approved the AquAdvantage salmon to go on the market，making it the first GM animal to be approved as food anywhere in the world．

　　GM foods are plants or animals that have been given a gene from another plant or animal to make them stronger in some way．The AquAdvantage salmon contains a gene from another type of salmon that makes it grow faster．

　　Although the FDA has said"food from the fish is safe to eat"，some believe that scientists can't completely understand the potential health risks of GM foods，simply because they're so new．Others worry that the fish could escape into the wild and cause ecological problems．

　　GM crops have experienced the same public argument，even though GM technology cuts down on the use of pesticides（杀虫剂） on crops and increases output．

　　While GM animals are new，GM crops have already appeared on our plates：A total of 28countries in the world including the US，Brazil and India planted 181.5million hectares （1.815million km2）of GM crops in 2014，according to the International Service for the Acquisition of Agri-biotech Applications．In China，we grow GM cotton and papaya and import GM soybeans，corn，rape，cotton and beets from abroad．

　　Due to safety worries，many countries have regulations for producing and selling GM foods．

　　In European Union countries，each GM food must be approved before it can be used．This process can take up to 17months．The origin of all GM foods must also be traceable，and all food with a GM content of more than 0.9percent must also be labeled，according to EU website europaeu．

　　The US is less strict about GM foods．Accordi