Genetic modification (GM) is in fact far more than a mere development of selective breeding techniques. Combining genetic material from species that cannot breed naturally is interference in areas which may be highly dangerous. The consequences of this kind of manipulation cannot be foreseen. It seems undeniable that these processes may lead to major benefits in food production and the environment. There is no doubt, for example, that some medical advances may have saved millions of lives. However, this level of technology can contain a strong element of risk. Our ignorance of the long-term effects of releasing GM plants or even animals into the environment means that this step should only be taken after very careful consideration.(     )
A、转基因过程与传统的选择过程完全不同。
B、越过物种壁垒是一个危险的步骤,并且对这种发展的长期结果了解不足。
C、转基因过程类似于自然选择。
D、转基因过程不应被标记为“干扰自然”。