CAN ANYONE BEAT THE MERCEDES?

The start of the 2014 season have been dominated by the two Mercedes and their drivers Lewis Hamilton and Nico Rosberg. And now the main question is if can anyone beat the Mercedes? And if the answer is yes, who is going to beat them?
We don't know the answer yet, but in the next Grand Prix in Spain we could know maybe one of these. Because almost always in the Spanish GP all teams bring new pieces for the car, sometimes succesfully and sometimes unsuccesfully, also the main important candidates, are Fernando Alonso with the Ferrari and the two Red Bull drivers, the world champion Sebastian Vettel and Daniel Ricciardo, so we will see.