The unemployment that results from the process of matching workers and jobs is sometimes called ( ) A: cyclically unemployment. B: frictionally unemployment. C: seasonally unemployment. D: structurally unemployment.

【单选题】Which of the following is incorrect? A. Tidal breathing is alsocalled cheyne-stokes respiration. B. Cheyne-stokes respirationwaxes and wanes cyclically so that periods of deep breathing alternate withperiods of apnea (no breathing). . C. Intermittent breathing ischaracterized by unpredictable irregularity. Breaths may be shallow or deep,and stop for short periods. D. Intermittent breathing is less severe than the tidal breathing