To put a lid on property speculation and plug the hole in municipal finances, China's property taxes will have to cover more homes in more cities.

ECONOMIST: One year on, China��s most-hyped tax is still mostly hype

The second suggests that a rod-like plug can block the hole by slipping across it sideways and stopping large ions from passing, rather like a drain cover stops leaves from entering the mouth of a pipe.

ECONOMIST: Synthetic biology: Expanded vocabulary | The