新GRE考试辅导：阅难难句的攻克（27）

会计考友

51.They are called virtual particles in order to distinguish them from real particles，whose lifetimes are not constrained　in the same way，and which can be detected.  
　　它们被称为“虚粒子”(virtual particle)，以便与实粒子(real particle)区分开来，而实粒子则不会以这种方式受到制约，并且其存在可得以测定。
　　52. Other theorists propose that the Moon was ripped out of the Earth‘s rocky　mantle by the Earth’s collision with another large celestial body after much of the Earth‘s iron fell to its core.
　　其他的理论家提出，在地球的大部分铁沉入到地核之后，由于地球与另一个庞大的天体发生碰撞，月亮便从地球那石质的地幔中撕裂开来而形成的。