已知x =＋，則x的值屬于區(qū)間(  )．

(A)．(－2，－1)           (B)．(1，2)

(C)．(－3，－2)           (D)．(2，3)

已知lga，lgb是方程2x－4x＋1 = 0的兩個根，則(lg)的值是(  )．

(A)．4               (B)．3                 (C)．2                     (D)．1

設a，b，c∈R，且3= 4= 6，則(  )．

(A)．=＋          (B)．=＋ 

(C)．=＋          (D)．=＋

已知函數(shù)y = log(ax＋2x＋1)的值域為R，則實數(shù)a的取值范圍是(  )．

(A)．0≤a≤1           (B)．0＜a≤1           (C)．a≥1               (D)．a＞1

已知lg2≈0.3010，且a = 2×8×5的位數(shù)是M，則M為(  )．

(A)．20                (B)．19                (C)．21                  (D)．22

若log[ log( logx)] = 0，則x為(  )．

(A)．             (B)．              (C)．                 (D)．

若0＜a＜1，函數(shù)y = log[1－()]在定義域上是(  )．

(A)．增函數(shù)且y＞0                                (B)．增函數(shù)且y＜0 

(C)．減函數(shù)且y＞0                                (D)．減函數(shù)且y＜0

已知不等式log(1－)＞0的解集是(－∞，－2)，則a的取值范圍是(  )．

(A)．0＜a＜           (B)．＜a＜1         (C)．0＜a＜1       (D)．a＞1

若lg2 = a，lg3 = b，則lg=_____________

已知a = log0.8，b = log0.9，c = 1.1，則a，b，c的大小關系是___________