题目

不同物种之间很难通过杂交培育新品种,可以打破物种界限进行育种的方式是( ) A.诱变育种 B.杂交育种 C.单倍体育种 D.转基因育种 答案:D【分析】 1、四种育种方法: ①杂交育种 :方法 :杂交 → 自交 → 选优;原理为基因重组 。 ②诱变育种 :方法 :辐射诱变、激光诱变、化学药剂处理;原理为基因突变。 ③单倍体育种 :方法 :花药离体培养、秋水仙素诱导加倍;原理为染色体变异(染色体组先成倍减少,再加倍,得到纯种)An American shopper, Emma Mumford, who was named “the Coupon(优惠券) Queen” has spent just 350 on a luxury(奢侈) Christmas for her and her family—but got 2,500 worth of food, drink and presents thanks to coupons and offers.Ms Mumford is a so-called “extreme coupon ” and spends hours hunting out the best deals and bargains. She has been preparing for this Christmas since the end of the last one. Ms Mumford made the huge savings by checking price comparison websites and as a result collected more presents than she needed for Christmas. After sorting out gifts for all of her family, she has even been able to donate 1,000 worth of presents to her local hospital.“It has been so nice to have Christmas sorted and not having to worry about breaking the bank. I wanted to get high quality presents for my family and show that you can do it without spending a fortune. There is a misunderstanding that everyone who does couponing only gets value products but through my careful shopping I have managed to purchase designer perfumes(香水), a high-end coffee machine .”she explained.She said “What started as a hobby to help me save money has turned into my life and I am able to run a business helping people save money. I know what it feels like to struggle as my ex-partner had a lot of debt which I took on for him. We were in a poor situation where every penny counted. That’s what really inspired me.”She has now turned her bargain-huntingspan> addiction into a business where she searches for the best deals and offer tips to the general public through video blogging and her Facebook Page.“I try and show people that it is just a little bit of work in the beginning but it will eventually pay off. One of the best things to do is just to be a bit forward thinking and save throughout the year.” 【1】How did Emma make the huge savings?A. She compared prices through websites.B. She hunted out bargains in real shops.C. She used coupons and offers worth 2,500.D. She collected more Christmas presents than needed.【2】What does “breaking the bank” in the third paragraph mean?A. Buying presents of low quality.B. Spending more money than you have.C. Breaking into the bank.D. Taking out money from the bank.【3】What really inspired Emma to help people save money?A. Her addiction to bargain-hunting.B. The financial difficulties she shared with her ex-partner.C. The poor situation people around her were going through.D. Her experience of running an unsuccessful business.【4】Which of the following can best describe Emma?A. Ambitious and stubborn.B. Sensitive and determined.C. Brave and lucky.D. Careful and caring.
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