That changed with the invention of cloning technology.

不过，随着克隆技术的进步，情况变得不一样了。

youdao

But they are difficult to make and require the use of an embryo or cloning technology.

但是制造他们是很困难的，而且需要使用胚胎或者是克隆技术。

youdao

Yet variations on cloning technology are already used in biotechnology labs all across the country.

但是，国内所有的生物工艺学实验室都已经使用克隆技术的种种变体了。

youdao

Right now, cloning technology is very unreliable--with only a handful of successes for every attempt in animals.

FORBES: Cloning People Easier Than Profits

In his State of the Union address, President George W. Bush advocated outlawing all use of cloning technology on human cells.

FORBES: Magazine Article

Many doctors, including some at the forefront of cloning technology, have expressed severe doubts about whether the techniques could ever ethically be used on humans.

BBC: 'Ban IVF for smokers and drinkers'