GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 6DD7E3BIS3LVB01RA

Scientists reported last month on a sign of relative solar ____________; the solar wind, a rush of charged particles continually spewed from the Sun at a million miles an hour, had diminished to its lowest level in 50 years. A. quiescence B. turbulence C. isolation D. calm E. remoteness F. instability