There has been great progress in the study of genetics.Doors 1.have been opened(open) up to technologies that never existed before.

　　2．Ways(way) in which a plant or an animal can be genetically modified.First，new material can 3.be inserted (insert) into its DNA to give the plant or animal 4.qualities (quality) which it would never have in nature.Second，material can be taken from 5.the DNA of a plant or an animal in order to remove qualities 6.which/that are not desired.

　　Aims of GM research：One aim of GM research is 7.to produce (produce) food which will make us 8.healthier (healthy)．Supporters of GM food argue that GM plants have larger harvests.

　　Questions about GM food：No one 9.really(real) knows whether it is safe for animals or humans to eat.No one knows what effects the GM material might have 10.on the food chain.