[填空题]
The Tevatron accelerator at u)i04s 8hxo 2onc3jq9zhs4j sFermilu,1 qb,uk :i6j(gw yjx*m:a baab (Illinois) is designed to carry an 11-mA beam of pq *6k (u:bmbuiwj ,x1 a,:ajygrotons traveling at very nearly the speed of light ($ 3.0\times10^{8 }\;m/s$) around a ring 6300 m in circumference. How many protons are stored in the beam? $ \times10^{12 }\;protons$
