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沈阳市初中物理毕业会考曾出过下面一道选择题: 如图1所示,一金属环,环上有一开口,当给它加热时,环上开口的距离将().
The junior high school physics graduation examination in Shenyang had a multiple choice question: As shown in Figure 1, a metal ring has an opening on the ring. When it is heated, the distance of the opening on the ring will be ().