在棱长为1的正方体ABCD﹣A1B1C1D1中，E为棱BC的中点，F为棱DD1的中点．则异面直线EF与BD1所成角的余弦值是

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在棱长为1的正方体ABCD﹣A₁B₁C₁D₁中，E为棱BC的中点，F为棱DD₁的中点．则异面直线EF与BD₁所成角的余弦值是（　　）

A： $\frac{\sqrt{2}}{3}$

B： $\frac{2 \sqrt{2}}{3}$

C： $\frac{\sqrt{3}}{4}$

D： $\frac{\sqrt{3}}{6}$

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B

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I'm Simon from America. I am twelve and I'm at Wllize junior School(初中). This month We have two school events(事件). One is an English party and one is a school trip. Next month, there will be five events.

Here is a list.

Date	Event
May12	School Day
May15-17	English speech Contest 3:00pm--4:30pm
May18	Volleyball game 2:00--3:30pm
May19	Art Festival 19:00am--5:00pm
May24	Music party 6:00--9:00pm

I'm in the school volleyball club. 1 also like singing. 1 want to play in the volleyball game and sing at the music party. 1'm very happy.

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