[填空题]
The voltage across th xruj+fw bcgfl y :/xrtc.(;) 6 moj,dqa2-3fqe deem+cg,nf+6abdf0d6pxsw s;7 us of a cyclotron is 55 kV. How many revolutions do protons make to reach a kinetic energy of 25 cbdss7+dmfn6g uwpx ,;+60 faMeV? $\approx $ $\ \text{revolutions}$
