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邻边不相等的平行四边形纸片，剪去一个菱形，一个四边形，称为第一次操作：在的四边形纸片中再剪去一个菱形，又剩下一个四边形，称为第二次操作；…依次类推，若第n次操作的四边形是菱形，则称原平行四边形为n阶准菱形．如图1，?ABCD中，若AB＝1，BC＝2，则?ABCD为1阶准菱形． (1)判断与推理： ①邻边长分别为2和3的平行四边形是________阶准菱形； ②小明为了剪去一个菱形，进行了如下操作：如图2，把?ABCD沿BE折叠(点E在AD上)，使点A落在BC边上的点F，得到四边形ABFE.请证明四边形ABFE是菱形． (2)操作、探究与计算： ①已知?ABCD的邻边长分别为1，a(a＞1)，且是3阶准菱形，请画出?ABCD及裁剪线的示意图，并在图形下方写出a的值； ②已知?ABCD的邻边长分别为a，b(a＞b)，满足a＝6b＋r，b＝5r，请写出?ABCD是几阶准菱形．
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【单选题】Now more people prefer a house in a coast city to ____ in such a large city as Beijing.
A.
that
B.
it
C.
the one
D.
one
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A.
interview
B.
cover
C.
approve
D.
compete
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A.
was
B.
have been
C.
has been
D.
were
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