问题
单项选择题
水平粱AB由铰A与杆BD支撑。在梁上O处用小轴安装滑轮。轮上跨过软绳。绳一端平地系于墙上，另一端悬挂重W物块。构件不计重。铰A的约束力大小为：（）.
A.A
B.B
C.C
D.D
答案
参考答案：A
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水平粱AB由铰A与杆BD支撑。在梁上O处用小轴安装滑轮。轮上跨过软绳。绳一端平地系于墙上，另一端悬挂重W物块。构件不计重。铰A的约束力大小为：（）.
A.A
B.B
C.C
D.D
参考答案：A
完形填空（共20小题；每小题1分，满分20分） It happened when I was a little girl. I can remember neither the beginning nor the end, but whenever I 36 it, tears flow down my face. When I was young, my family led a(n) 37 life in the country. As you can imagine, many country roads are difficult to walk on. One 38 we were visiting some relatives and the 39 was very bad. It began to 40 on our way back home. Dad carried me on his 41 . Mom gave her overcoat to my 42 . We walked together through the rain for more than an hour. I was fat at that time and Dad  must be 43 to hold me for such a long time. He  almost 44 down many times. In hope of 45 my father’s burden, I tried to carry myself, 46 I achieved nothing since I was just a little kid.When we arrived home, the inside of our house was 47 with rain water. The rain had come 48 our leaky（有裂缝的）roof and water was everywhere. Mom put bowls all around the house  to try to 49 the rain. Then she put me and my elder brother to 50 , carefully placing us on the remaining 51 place. I fell asleep soon. When I opened my eyes, I found Dad and Mom were 52 in chairs, both having caught bad colds.This is my very earliest 53 . Though the evening has long passed, and now we live a happy life, I won’t forget the rain we 54 together. The rain, that evening, and especially my parents’  55 , will stay in my mind forever.
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