A.既能進(jìn)行加法計數(shù)又能進(jìn)行減法計數(shù) B.加法計數(shù)和減法計數(shù)同時進(jìn)行 C.既能進(jìn)行二進(jìn)制計數(shù)又能進(jìn)行十進(jìn)制計數(shù) D.既能進(jìn)行同步計數(shù)又能進(jìn)行異步計數(shù)