题目

如图甲所示,将一块质地均匀的长木板平放在水平桌面上,用水平力F向右缓慢推动木板,使其右端渐渐露出桌面,如图乙所示.在推动木板,使其右端渐渐离开桌面边缘至木板中心到达桌面边缘的过程,长木板对桌面的压力    , 压强    , 如果水平推力F一直保持不变,则木板受到 的摩擦力将会   (选填“变大”“变小”或“不变”)There are plenty of _______ in our school.   They work very hard.A.woman teachersB.woman teacherC.women teachersD.women teacher
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