2022初三英语周报答案。

(19)(本小题满分12分)解:(1)连接BD,设AC与BD的交点为F,连接EF因为E为B1D中点,F为BD中点,所以EF∥BB1,因为BB1⊥平面ABCD,所以EF⊥平面ABCDD又因为EF在平面ACE内,所以平面ACE⊥平面ABCD6分B(Ⅱ)由已知有AA1DD1,即直线AE与AA1所成角的余弦值为连接AE,设AE=x,则A1E=x,在△AAE中,由cos∠A1 x2-x2√32·1·x3解得:=√3所以AC=√AC2-4=√,即菱形ABCD为正方形,所以有EF=24=2AD=CD=所以三棱锥C一ADE的体积3×BF×2×AD×CD=1212分

ear jonaIm glad to hear from you and i d like to share withyou something about serving chopsticksi As you know, people in China are encouraged to useserving chopsticks, which are different from personal chopticks in shape and colour serving chopsticks are used totake food from shared dishes. You can add food to yourbowl with them, but never place them into your mouth oryour own bowlUsing serving chopsticks benefits everyone at tableFirst of all, it prevents diseases from' spreading while weare eating together. We can also use them to put food intoothers bowls, thus creating a pleasant and harmoniousdining atmosphereHoping you'l come to China to experience themfirst handYoourL i hua

以上就是2022初三英语周报答案。，更多英语周报答案请关注本网站。