A new medical technology can be used clinically only if it is effective and safe. In 1998, American scientists successfully made human embryonic stem cells grow and proliferate in vitro. if this stem cell technology is combined with cloning technology, the necessary tissue cells can be cultured from patients' somatic cells to replace patients' damaged cells. to treat a variety of difficult diseases, this is the so-called therapeutic cloning. But now therapeutic cloning is still a long way from clinical use.
If true, the statement 'So far, it is quite difficult to obtain human embryonic stem cells' will give the above conclusion the strongest support.