如图，游客在点A处坐缆车出发，沿A﹣B﹣D的路线可至山顶D处，假设AB和BD都是直线段，且AB=BD=600m，α=75°，β=45°，求DE的长．

（参考数据：sin75°≈0.97，cos75°≈0.26， $\sqrt{2}$ ≈1.41）

—Don't make so much noise in class, Jack!

—         .

阅读理解
    Do you know some world famous brands (品脾), such as Nike, adidas, Kappa...？ What do you think of them？ Do you use their products(产品)？ Here are some students' opinions:
Sam: I am a Nike fan. Many of Nike's advertisements are fun and its products are great! I have a pair of Nike basketball shoes.
Joe: In my eyes, top brand means high quality, So I love top brand products though they're very expensive. I was glad Mum bought me a Kappa T-shirt last month.
Sally：The logos(标识) of famous brands are usually unique and nice. It's cool to own products with those logos. Sometimes I wear my adidas coat.
Jack：Many top brand products are advertised by spokesmen(代言人). I love the spokesmen of many top brand products. I've got many Nike socks.
Susan: I know it's popular for young people to have famous brand products these days. But my parents both lost their jobs. I have no interest in following the fashion. I only choose the products that are not expensive.
Adam: As a student, I don't earn money myself. It's not easy for my parents to support me. So I only use some ordinary products. I don't agree students use the famous brand products.

已知函数f（x）=ax²+1（a＞0），g（x）=x³+bx．

把下列词语补充完整。

____ ____粼粼     ____ ____私语

____无天____    笔____ 龙____

独____匠____     ____ ____共赏

妙____生____    引人____ ____