A mobile is a piece of art that hangs from a ceiling. You may remember one hanging from the ceiling in your bedroom.
风铃是一种悬挂在天花板上的艺术品。您或许还记得自己卧室天花板上挂着的一个。
A mobile consists of sticks and figures. Each stick has a few points to which figures or other sticks may be attached.
一个活动挂图由木棍和图形组成。每根木棍上有几个点，图形或别的木棍可以连接在这些点上。
Also, each stick has a hanging point, from which it is attached to a stick further above (or to the ceiling).
此外，每根棍子都有一个悬挂点，通过这个点它被连接到上方更高处的棍子（或者天花板）。
The following example mobile can be described using these numbers and brackets:
以下这个示例手机可以用这些数字和括号来描述：
(-3 (-1 1) (1 1)) (2 3)
Question: 问题:
Which of the following mobiles is described by the following instructions:
以下哪款手机符合以下描述：
(-3 (-1 4) (2 (-1 1) (1 1))) (2 (-1 6) (2 3))
A. 
B. 
C. 
D. 
Explanation 解释
正确的答案是A.
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