已知:2m=3,4n=8,求:23m﹣2n+3的值.
解:∵2m=3,
∴23m=27,
又∵4n=8,
∴22n=8,
∴23m﹣2n+3=23m÷22n×23=27÷8×8=27.
Some of the doctors are paid almost ______ as the nurses.
A.twice as much
B.much as twice
C.as much twice
D.as twice much
飞行员前4分钟用半速飞行,后4分钟用全速飞行,在8分钟内一共飞行了72千米,则飞机全速飞行的时速是( )。
A.360千米
B.540千米
C.720千米
D.840千米