某种气体在不同温度下的气体分子速率分布曲线如图所示,图中f(v)表示v处单位速率区间内的分子数百分率,由图可知( )
A:气体的所有分子,其速率都在某个数值附近
B:某个气体分子在高温状态时的速率可能与低温状态时相等
C:高温状态下大多数分子的速率大于低温状态下大多数分子的速率
D:高温状态下分子速率的分布范围相对较小
B
Happy Middle School
We're a bilingual(双语的) school for children of 6~15.We want a cook,a library assistant, a sports coach and a language teacher.
Jobs
Ages
Languages
Skills(技能)
Others
cook
25~40
Chinese
can cook Chinese and Western food
healthy
library
assistant
20~35
Chinese,
English
can read different kinds of books
careful
sports
coach
20~40
Chinese,
major in(主修) P.E.
and strong
language
teacher
—
major in English
计算:
(1)﹣t3•(﹣t)4•(﹣t)5;
(2)(b2n)3(b3)4n÷(b5)n;
(3)tm+1•t+(﹣t)2•tm(m为整数);
一个长方形操场,长160米,宽120米。如果把它画在比例尺是1:4000的地图上,长____ 厘米,宽____ 厘米