已知log23=m,试用m表示log69=______.
log69=log29log26=2log231+log23=2m1+m.
故答案为:2m1+m.
A crab has ____________ legs and a duck has ____________ legs.[ ]
A. four, two
B. two, two
C. two, four
D. eight, two
一静止电子开始经电压为U1的加速电场加速后,又垂直于电场线进入电压为U2的两平行金属板间的偏转电场,射出偏转电场时沿电场线方向偏移量为y,要使y增大,则应:( )
A.U1、U2都增大
B.U1、U2都减小
C.U1减小、U2增大
D.U1增大、U2减小