GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 0O4XN27J57JVV8YBA

The theory that the 1908 Tunguska event was the explosion of a cosmic body in the sky over Siberia is ____________: no one has yet found fragments of the object or any impact craters in the affected region. A. long-standing B. indisputable C. plausible D. uncontested E. unproven