GRE Text Completion: Manhatton-GRE填空Manhatton - AW6306FC01T67DA7=

The new particles produced by CERN's Large Hadron Collider are ____________, lasting a millionth of a billionth of a billionth of a second before disintegrating into photons, quarks, or other particles. A. ephemeral B. infinitesimal C. myriad D. poignant E. fleeting F. countless