题目

某化学小组在进行模拟炼铁的实验时，对产物的成分进行探究。 【提出问题】黑色粉末A可能是什么呢？ 【查阅资料】铁的氧化物都能与稀盐酸，稀硫酸反应，其中氧化铁为红棕色，其余都为黑色，并且只有四氧化三铁能被磁铁吸引。 【进行猜想】小组成员一致认为：黑色粉末A不可能只有铁粉，理由是        ， 黑色粉末A加入足量CuSO4溶液所发生反应的化学方程式是          。 小组成员，通过查阅资料，对黑色粉末A的成分进行了如下猜想：任务型阅读 There are many times we need to give gifts . Keep these tips in mind as you’re thinking about what gift you’ll give.Gift giving dosLeave the price label in the bag if it is an expensive gift so that others can see how much they need to give back. Remember to hold the gift in both hands to give gifts.Gift giving don’tsDon’t worry about what card to take with the gift. Cards are seldom used in China, so a Chinese wouldn’t expect a card along with a gift. Choosing the right gift*Gifts for familyWhen you’re meeting your partner’s family, a gift is expected, food or fruit baskets are good if you have no idea what to give. If your hometown is known for a special food, buy some to take as gifts.*Gifts for friendsYou can spend less money on friends than you do on family. Books, wallets, key rings and special foods like chocolate or coffee are good enough.*Gifts for business partnersWhen you’re starting a business relationship, a tasteful gift will be better. Pens from your company or with the receiver’s name is a practical gift. Local snacks from your area is a great gift too. Gifts to avoid（避免）You should remember not choose anything because of the cultural symbolism（文化象征） or the word shares a similar pronunciation to some bad things. Clocks, in Chinese, to give a clock has the same pronunciation as the phrase “songzhong”. Umbrellas and shoes are not good gifts in China. In all, a thoughtful gift is great when you want to thank a friend, say goodbye to someone or meet families.【1】 for giving a giftGift giving dos and don’ts* Leave the price label in the bag if the gift isn’t 【2】.* Give the presents in both hands.* Don’t 【3】 about what card to take with the gift.【4】 to choose the right gift* When meeting your partner’s family, it’s good to 【5】 food or fruit baskets or a special food from your hometown.* Spend 【6】 money on family than you do on friends.* To 【7】 the a business relationship, pens from your company or with the receiver’s name is practical.* Don’t choose gifts 【8】 a clock or an umbrella because of the word shares a similar pronunciation to【9】 bad.A thoughtful gift is great when you want to do something like 【10】 a friend, saying goodbye to someone and so on.