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英語 高校生

(2)が分かりません。分離と精製の種類は学びましたが、どうやって区別すれば良いか分からず困っています。例えば(ア)では、ろ過でもいいのではないか?と思ってしまいます。また、類題1のアですが、再結晶ということは硫酸銅も少量ということでしょうか?一問でもいいので解説お願いします。

(2) 次の操作は, 分離・精製の方法として何がふさわしいか。 その名称を答えよ。 (ア) 海水を, 水と塩化ナトリウムなどの成分に分ける。 (イ) ごま塩から塩化ナトリウムを得る。 (ウ) 牛乳の中の油分を取り出す。 (エ) 黒色の水性サインペンの色素の成分を確認する。 考え方 (1) (ア) 水溶液は混合物である。 (ウ) 空気は, 窒素・酸素・その他からなる。 (エ) 炭酸水素ナトリウムのことである。 (オ) いろいろな油が混合している。 答 純物質:イ,エ 混合物 アウ,オ (2) (ア)蒸留すれば, 純粋な水と塩化ナトリウ 類題・ 1 ..... ムなどに分離できる。 (イ) 水に溶かしてろ過し, 塩化ナトリウム水溶 液を得て, 水を蒸発させる。 (ウ) エーテルなどの溶媒を用いると、 油分を抽 出できる。 答 (ア) 蒸留 (イ) ろ過 (ウ) 抽出 (エ) クロマトグラフィー 次の分離・精製に最も適した操作法(複数の場合もある) を答えよ。 (ア) 少量の砂と硫酸銅(ⅡI) を含んだ硝酸カリウムから硝酸カリウムを取り出す。 (イ) ウイスキーからアルコールを取り出す。

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英語 高校生

2011年北海道大学の英作文の添削をおねがいします。questionCです。 字数が足りていませんが、それ以外の部分をおねがいします。

Australia, the United States, and urban India. Rend the following passage and answer questions A through C in English. while their wives work outside the home, Stay-at-home dads are also called stay- Stay-at-home dads are married fathers with children who care for their family domestic burden has led some couples to completely reverse their roles. The number of stay-at-home dads is starting to increase in Britain, Canada, 「husband who can do the housework, such as shopping, cooking, and looking alter the children. The widespread expectation that men should share the vin England showed that 75 percent of women in their twenties prefer a 38 on were breadwinners and women were caregivers. Arecent Traditionally, Survey can Many stay-at-home dads take great pleasure in showing affection to their children. Their wives can pursue careers without worrying about teaching family values or paying for child care. Research suggests that children of stay- athome dads often benefit from strong bonds with both parents, whereas the father's role ina stay-at-home mom household is less influential. Although the number of stay-at-home dads is increasing, it remains small Compared to the total number of fathers. In the United States, the government estimates that in 2009 there were 158,000 stay-at-home dads, a mere 0.2 percent of 67.8 million fathers. In Australia, about 1 percent of fathers are stay-at-home dads. In urban India, one estimate suggests 3 percent of fathers stay at home full-time. Some stay-at-home dads suffer from social stigma. Many people, including stay-at-home moms, do not understand why a man would choose to give up his career to care for his family full-time. Being a stay-at-home dad can also be career suicide. Many employers view stay-at-home dads as lacking ambition and commitment. Losing professional skills may prevent stay-at-home dads from returning to the workforce.

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英語 高校生

QuestionAとBの1について、私の回答で丸はもらえますか?教えていただきたいです 北大2017年の英作文の問題です。

Read the following passage. for my age. I leave home early and it takes about two hours on a crowded train to get to the office. I get Sunday off, but on the other days I'm usually in my office till nine o'clock, or even midnight on occasion. But I enjoy seeing the customers excited about our new products and services. Every August I take a 15 years. It's a secure job in a major company and I enjoy a relatively high salary six-day summer vacation, usually at my parents' place in Toyama. It's nice to Thave been working for a Japanese cell phone company in Tokyo for the last 2017年度(3] 32 a or the space of the countryside after my cramped apartment in the suburbs. However, I spend two days travelling there and back, and then it's straight back to work the next day. Last summer, however, I was able to take 10 days off in August and used the rare chance to take my wife on a foreign holiday by going to visit my old friend, Pierre, in Paris. He and I met at university in the US nearly 20 years ago when we were both international exchange students. We shared a love of tennis and S0on became good friends, and have stayed in touch. He now works as a supervisor in a post office in eastern Paris. It was lovely to see Pierre again and spend time in the spacious apartment he shares with his wife. I was very surprised to find that they were just back from a month-long summer vacation in southern France and Switzerland. Pierre told us that this is perfectly normal in his job, and couldn't believe his ears when I mentioned that my usual vacation is around a week and that I work 12 hours a day, six days a week. His usual workday, he said, was from 9:00 to 16:00. He wasn't joking ; he was back home by bicycle by 16:20 every day. He likes his job as the postal service fulfills a vital function in society by connecting people both aomestically andinternationally. On hearing his story, though, I began to reflect upon my own life and work. AmI working to live, or just living to work ? Answer questions A to C in English. You may use words and ideas from the Lext, but you must not copy complete sentences.

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英語 高校生

解答では背理法を使っているのですが、この証明方法でも大丈夫でしょうか?

117 次の等式を満たす有理数 p, qの値を求めよ。 第2章 集合と命題 29* 113 実数 x が正の無理数であるとき, /x は無理数であることを証明せよ。 STEPくB 例題 13 nは整数とする。次の命題を証明せよ。 n°が3の倍数ならば, nは3の倍数である。 対偶を証明する。3の倍数でない整数nは, 3k+1, 3k+2(kは整数)のいずれかの 形で表される。 対偶「nが3の倍数でないならば, n° は3の倍数でない」 を証明する。 nが3の倍数でないとき, nはある整数えを用いて 3k+1, 3k+2のいずれかで表さ 指針 解答 れる。 こ de [1] n=3k+1のとき n=(3k+1)°=27k°+27k°+9k+1=3(9°+9k°+3k)+1 9°+9k°+3kは整数であるから,n°は3の倍数でない。 12」 n=3k+2 のとき ケ効半ふ 変 n°=(3k+2)°=27k°+54k°+36k+8=3(9k°+18k?+12k+2)+2 9°+18k°+12k+2は整数であるから, n° は3の倍数でない。 よって,対偶は真である。したがって,もとの命題は真である。終 114 m, n は整数とする。次の命題を証明せよ。 (1) n?が5の倍数ならば, nは5の倍数である。 *(2) mn が3の倍数ならば, m, nの少なくとも一方は3の倍数である。 115 V6 が無理数であることを用いて,V3-V2 は無理数であることを証明せ 太関 よ。 T16 p, gが有理数,Xが無理数で, か+qX=0 であるならば, カ=q=0 であるこ とを証明せよ。 =1 1)0ta?=2+V2 2-1

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