如图,正方形 ABCD 中，点 E ， F 分别是 DC ， BC 的中点，那么 EF⇀=_刷题宝

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如图,正方形 ABCD 中，点 E ， F 分别是 DC ， BC 的中点，那么 EF⇀= （）

A： $\frac{1}{2} \overset{⇀}{A B} + \frac{1}{2} \overset{⇀}{A D}$

B： $- \frac{1}{2} \overset{⇀}{A B} - \frac{1}{2} \overset{⇀}{A D}$

C： $- \frac{1}{2} \overset{⇀}{A B} + \frac{1}{2} \overset{⇀}{A D}$

D： $\frac{1}{2} \overset{⇀}{A B} - \frac{1}{2} \overset{⇀}{A D}$

上一题下一题 0.0难度选择题更新时间:2019-11-19 06:53:12

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D

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