—I agree. Trees are getting now.
A:from, fewer and fewer
B:for, more and more
C:for, less and less
D:from, more and more
利用SC108B型计算器计算
已知:梯形面积公式为S=12a+bh,其中a=84.3,h=64.3,S=6846.求b(精确到0.1)
半径R=0.9m的四分之一圆弧形光滑轨道竖直放置,圆弧最低点B与长为L=1m的水平面相切于B点,BC离地面高h=0.45m,C点与一倾角为θ=30°的光滑斜面连接,质量m=1.0kg的小滑块从圆弧顶点D由静止释放,已知滑块与水平面间的动摩擦因数µ=0.1,取g=10m/s2.求:
(2015•枣庄)如图,平面上直线a,b分别经过线段OK两端点(数据如图),则a,b相交所成的锐角是____ .