A:崩塌、滑坡、泥石流、水土流失
B:崩塌、滑坡、洪涝、干旱
C:泥石流、地面沉降、土地盐碱化、干旱
D:水土流失、干旱、泥石流、土地盐碱化
两电阻R1、R2的电流I和电压U的关系如图所示,可知两电阻R1:R2等于( )
若loga 2 <1,则实数a的取值范围是____.
A. Your B. May C. erasers D. violin E. library F. Can G. His H. shop I. piano J. rulers