The geologic story the Opportunity read there always spoke of an ancient martian wasteland of windblown dunes pocked by the occasional acid-laced puddle.
Educators may fear that children hearing two languages will become permanently confused and thus their language development will be delayed; this concern is not documented in the literature.
The researchers are confident that a similar switch exists in the human brain - and say that drugs that capitalise on their discovery could be in use in ten years.
As long as this gap exists, there will always be a possibility that new conflicts and jealousies will emerge, or rather that the old conflicts will re-appear, but between different groups.
Although 174 nations approved the admittedly flawed Kyoto accords to reduce carbon levels, the arguments between the US and the EU on this issue still exist.