若梁的受力情况对于梁的中央截面为反对称(如图)，则下列结论中正确的是()。
A. Q图和M图均为反对称，中央截面上剪力为零
B. Q图和M图均为正对称，中央截面上弯矩为零
C. Q图反对称，M图正对称，中央截面上剪力为零
D. Q图正对称，M图反对称，中央截面上弯矩为零
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如图所示一支架，荷载F=40kN，三根杆的材料相同，弹性模量E=200GPa，各杆的横截面面积分别为A1=200mM2，A2=200mm2，A3=400mm2，则各杆的内力为()。
A. F1=35.5kN，F2=10.76kN，F3=7.5kN
B. F1=22.5kN，F2=8.96kN，F3=12.4kN
C. F1=35.5kN，F2=8.96kN，F3=7.76kN
D. F1=35.5kN，F2=25.2kN，F3=7.76kN
出纳员不能删除支票登记账中已报销支票。()
A. 正确
B. 错误
在开关S闭合瞬间，图示电路中的iR，iL，iC和i这四个量，发生跃变的量是()。
A. iR和iC
B. iC和i
C. iL和iC
D. iR和i
听力原文：M: Why were you late for work today？
W: I overslept and missed the train.
Q: Why was the woman late？
(10)
A. She got up later than usual.
B. She took the wrong train.
C. She forgot that she should work.
D. The train was late.
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