Examining the evolution of one protein, a team of scientists declares the answer is no, saying new mutations make it practically impossible for evolution to reverse direction.
It is practically impossible to know what someone is really worth, given private businesses, illiquid assets, debts, collections and assorted Swiss bank accounts.
While Beijing has held out the possibility of rescheduling the visit, this was practically impossible given that the Expo ends next month.
Palestinians feel that a viable state is practically impossible, so deeply has Israel encroached on their land and dismembered their society.
Dieter Graumann, president of Germany's Central Council of Jews, asserted that the verdict, if it is upheld, would make Jewish life in Germany, just as it is blooming again, practically impossible.
At 7 a.m. on a recent spring day, many passengers are pecking at BlackBerries and talking on mobile phones, but eavesdropping is practically impossible because too many languages are in play.
