[单项选择]A new biotechnology procedure that could become commercially available in as little as two to four years is "transgenesis", which permits scientists to create an animal with specific traits by adding, removing, inactivating, or repairing genes in an embryo. The additional genes can come from any source. For example, if a gene of interest occurs in mosquitoes—say, one that codes for resistance to a certain disease—it can be removed and places in the embryo of a farm animal. The several strains of commercially useful transgenic farm animals that will probably emerge in the next few years could include leaner pigs, poultry resisting to influenza or other deadly diseases, sheep with wool that is easier to wash, and goats that produce valuable pharmaceuticals in their milk.
The simplest way to make transgenic animals is to inject a gene into a one-cell embryo and then implant the embryo in another animal. Under the right conditions, the new gene joins one of the embryo’s strands of gen
A. this procedure is available only on the market
B. this procedure can be used in producing better farm animals
C. This procedure can be used to promote business
D. People such as farmers can use this procedure in their production