When you buy cooking oil in the supermarket, you may notice that some brands are labeled as "GM (genetically modified)-free". So, what is genetic modification? Are GM foods safe? These questions have been put back into the spotlight recently. On Nov 19, the Food and Drug Administrati0n (FDA) in the US announced that it had approved the AquAdvantage salmon to go on the market, making it the first genetically modified 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 controversy, even though GM technology cuts down on the use of pesticides on crops and increases yields. While GM animals are new, GM crops have already appeared on our plates: A total of 28 countries in the world including the US, Brazil and India planted 181.5 million hectares (1.815 million km2) of GM crops in 2014, according to the International Service for tile 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 food. In European Union countries, each GM food must be approved before it can be used. This process can take up to 17 months. The origin of all GM foods must also be traceable, and all food with a GM content of more than 0.9 percent must also be labeled, according to EU website europa.eu. The US is less strict about GM foods. According to FDA regulations, companies introducing new GM foods to the market should report them at least 120 days before release. The labeling is voluntary, except that a product cannot be labeled as "GM-free" if genetically modified materials are used. In China, GM foods can only be produced after strict tests by the Ministry of Agriculture say that they are safe. All food that is made from GM crops or contains GM ingredients must be clearly labeled on the wrapper. One of the reasons for many people to worry about the AquAdvantage salmon is that  _  .
the gene that makes them grow faster can work on humans too there are possible health risks that even scientists might not have figured out yet they could possibly become threats to other wild species they are not nutritious enough or might taste strange