如图所示,小球从高处下落到竖直放置的轻弹簧上,从小球接触弹簧到将弹簧压缩至最短的过程中(弹簧一直保持竖直) ( )A.弹簧的弹性势能先增大后减小 B.弹簧的弹性势能增加量大于小球重力势能减少量 C.小球的动能一直在减小D.小球的机械能守恒 答案:B
观察下列句子中的画线部分并将其译成汉语。
1.When are we leaving and when are we coming back?
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2.We are reaching Dali in Yunnan Province where our cousins Dao Wei and Yu Hang will join us.
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