如图，直线AD∥BE∥CF， $BC=\frac{2}{3}AB$，DE=6，那么EF的值是____ ．

It is August 2050. Mrs Peng and Mr Yu are writing about hotels and houses on their posts.

The Hotel Whale

  The Hotel Whale is built (A) 在水下. It is in the shape of a whale. This hotel has 50 bedrooms, a cafe and a shopping centre.

Mrs Peng: “When we were staying at the hotel recently, my children watched the fish outside their bedroom window. (B) They were never bored.”

Forever Green Houses

  These houses are both “green” and “smart”. There is glass outside the houses. Heat is held under the glass and is then used as energy for (C) each house. In the bathroom, your medicine cupboard is connected to your doctor’s computer. In the kitchen, your smart fridge tells the supermarket’s computer when you (D) need more food.

Mr Yu: “When we were living in our old house, we were using more energy. I would certainly recommend Forever Green Houses to my friends. (E) They will satisfy everyone.”

在成人的心肌细胞中，比平滑肌细胞显著增多的细胞器是

材料一：“有军功者，各以率受上爵；为私斗者，各以轻重被刑大小。僇力（尽力）本业（农业），耕织致粟帛多者，复其身；事末利（经商）及怠而贫者，举以为收孥（没收为官奴）……宗室非有军功论，不得为属籍……为田开阡陌封疆，而赋税平。”

——司马迁《史记·商君列传》

材料二：战国末期思想家韩非曾说：“商君说秦孝公以变法易俗而明公道……是以国治而兵强，地广而主尊……此亦功之至厚者也。”

——选自《韩非子》

材料三：西汉儒学家董仲舒曾说：“至秦则不然，用商鞅之法……除井田，民得买卖，富者田连阡陌（田地广阔），贫者亡（没有）立锥之地。”

——选自《朱子语类》