把10cm长的线段进行黄金分割，则较长线段的长（$\sqrt{5}$≈2.236，精确到0.01）是（　　）

节假日双休日，去野炊实为一大快事．然而，在野炊的情趣之中，如果遇到下面一些问题，你该如何处理？

（1）对野炊有经验的人会告诉你，餐具最好是导热性好，不易破碎的材料制成，你准备带的餐具是用　____  制成的；（填字母）

A．金属          B．陶瓷           C．无所谓

（2）野炊食谱如下：主食：馒头    配菜：红烧肉、豆腐汤、牛肉干．主食和配菜中主要含蛋白质、____ 、油脂、无机盐和水等营养素．

（3）用高锰酸钾制氧气时，收集到的氧气略显红色，可能的错误操作是____ ．

（4）用水将pH试纸润湿后，再测某稀盐酸的pH，结果____ （填“偏大”、“偏小”或“无影响”）．

（5）“低碳生活”是指生活作息时所耗用的能量要尽量少，减低二氧化碳排放量，从而减少大气污染，保护环境．下列做法符合“低碳生活”理念的是____ （填序号）．①节约使用天然气      ②提倡使用一次性木筷    ③大量砍伐森林树木．

       A hot dog is one of the most popular American food. It was named after frankfurter, a German food. You may hear “hot dog”1in other ways. People sometimes 2“hot dog” to express pleasure(快乐). For example, a friend may ask 3 you would like to go to the cinema. You might say, “Great. I’d love to. ” Or, you could say,”4! I'd love to go.” People 5use the expression to describe someone who is a “show-off”, who tries to show everyone else how 6he is. You often hear such a(n)7called a “hot dog”. He may be a basketball player, for example, who 8the ball with one hand making a(n) 9 catch seem more difficult. You know he is a “hot dog” because when he makes such a catch, he bows(鞠躬) to crowd, hoping to10their cheers.

下列各组中，不属于同一性状之间的差异的是（    ）