Questions 57 to 61 are based on the following passage. Genetically Modified (转基因的) crops are everywhere. It seems even in Europe, strict laws designed to keep the European Union free of GM crops and products are not working, instead are posing problems for the EU: Farmers’ representatives say that supplies of animal feed for poultry and pigs are being refused entry at European ports when found to contain even trace amounts of GM material. Under Europe’s "zero-tolerance" laws on GM, introduced in 2007, the presence of even a few seeds of GM material will rule out an entire shipment. The animal feed industry says that the laws are unworkable because GM material is almost unavoidable, given today’s global supply chain. "Though we understand the consumer concern in Europe, we don’t understand zero tolerance because it closes down trade," says Pekka Pesonen, secretary general of Copa-Cogeca, a federation of groups representing 15 million EU farmers in total. He claims that European pig and poultry farmers will go out of business unless the EU adopts a more practical checking approach by setting a standard -say 0.5 percent beneath which GM is tolerated. Pesonen says such "tolerances" operate for other pollution, including pesticides and heavy metals. So why not for GM material, much of which has been cleared for human consumption elsewhere in the world Last year 200 000 tons of conventional animal feed mainly soy and corn—were refused entry to the EU when they were found to contain small amounts of GM corn varieties. Then flax (亚麻) from Canada was found to contain traces of a GM variety named CDC Triffid that was withdrawn from commercial sale in 2001. Following a prohibition on flax more than 100 shipments were rejected, but trade is slowly resuming. The rejected tonnage is only a small part of the 32 million tons of feed imported each year. But it leads to delays to subsequent contracts, higher prices and reluctance by importers to risk further shipments. Prices will be higher still this year, says Pesonen, owing to natural disaster in South America and a growing market for American farmers selling crops to Asia, which accepts mixed shipments. Increasing numbers of GM crop varieties are on the way. At present, around 30 varieties are grown around the world, but that is predicted to double twice by 2015, screening more difficult than ever. A further conflict arises because all the European officials are due to be replaced in February. A spokeswoman for the health commission, which introduced the zero-tolerance policy to satisfy widespread questionings in Europe about the safety of GM crops, says that intensive discussion on feed imports have already taken place. "Once the new commission is established, it will have to consider how to proceed on this matter," she says.

European laws against GM products ______.