Which of the following statements is TRUE according to the passage?
Ronald Green doubts about the future successful birth of the so-called cloned embryo.
Dcotor Severino Antinori is strongly opposed to cloning human begins.
Up to now,seven kinds of animals have been cloned,including sheep,cats,humans and rabbits.
Professor Rudolf Jaenisch is carrying on an experiment on cloning an eight-week-old embryo.