如图所示，光滑圆球放在直角三角形木块和墙之间，整个装置处于静止状态，墙与球之间的弹力用F表示，三角形木块与地面之间的弹力用FN表示，三角形木块与地面之间的摩擦力用f表示，若将三角形木块向墙移动一小段距离，整个装置仍静止，则F、FN、f大小的变化情况是（）
A.F、FN、f均变大
B.F、FN、f均变小
C.F、FN、f均不变
D.F、f变大，FN不变
参考答案：C
Hello, boys and girls! My name 1 Frank. I am eleven. This is a 2 of my family. This is my father. 3 name is Dale Brown. He is a teacher in my 4 . He teaches English. And that is mother. She is a 5 , too. Who(谁) is this? Oh, he is my 6 —my father’s brother. My grandparents 7 in the photo. 8 are in the USA. That is my dog. 9 name is Dick. I love my 10 and I love my dog, too.
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