盒中有3个红球,2个黄球,3个篮球,从中取3个球,排成一列,共有()种排法。
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斯托克斯定律的表达式( )。
A. 6ηrυ
B. 3πηυ
C. 6πηrυ
D. 3πηrυ
斯托克斯定律对( )适用
A. 圆形颗粒
B. 任何形状颗粒
C. 线性颗粒
D. 球形颗粒
He wanted to make sure __________.
A. how we went there by bus
B. where did we go
C. what did we go there
D. when we went there
______ the Atlantic Ocean crosses the equator(赤道), the trade winds cause a flow of water to the west.
A. That
B. When
C. Where
D. Though