科学工作者将一株矮杆低产的小麦与一株高杆高产的小麦进行杂交，在后代植侏中，出现了矮杆低产、高杆高产、矮杆高产、高杆低产四种类型的小麦。请分析回答：
（1）人们应该选出其中哪种植株继续多代繁殖培育，从而得到有利于人类的新品种小麦？
。
（2）题中涉及到的小麦性状中，属于相对性状的有： 、 。
（3）杂交亲代中的矮杆低产和高杆高产性状在后代中依然出现，这种与亲代相似的现象叫
做 ，后代中出现了矮杆高产和高杆低产两种新类型，这种与亲代不同的现象叫做
。
(1)矮杆高产 (2)高杆与矮杆，高产与低产， (3)遗传，变异
高杆易倒伏，矮杆抗倒伏，所以应选用矮杆高产的品种，相对性状指的是同种生物同一性状的不同表现形式称为相对性状，本题中的相对性状有高杆与矮杆、高产与低产，生物体的亲代与子代之间，以及子代的各个体之间在性状上存在着差异的现象叫做变异，生物体的亲代与子代之间，以及子代的各个体之间在性状上存在着相似的现象叫做遗传。
Friends play an important role in our life. Most people hope that their friends will always be there. They _____ friendship to last forever. ____, even the best friendship can end. As time goes by, many friendships end because of a(n) ______ in personality or way of life. The friendship slowly loses importance and finally_______. Tommy wrote, “I didn’t even know the friendship was over until I caught myself thinking of Alan as a former friend.” Peter explained. “We _____ seeing each other less and less. The friendship was just over.” Sometimes friendships______ suddenly from a disagreement or move to another place. Alice said, “The end of our friendship was a gradual thing. I moved from one side of the city to the other. Since then we _____ made a phone call. We met less and less. At last our friendship ended.” Jack said, “ When I moved to Seattle after college, our friendship died. Both of us were always____ with new jobs, so we didn’t keep _____ touch with each other. Our friendship was so dead that I didn’t call him_____ I went home.” Yet the biggest problem to a friendship is change. Lillian Rubin in her book Just Friends say, “Generally it’s______ that friends will accept each other if they both remain what they were when they met, or change in similar directions. If they change or grow in different ways, the friendship most likely______ lost.” No matter why, when, or how friendships end, there is always_____ pain of loss. When nothing can be____ to keep the friendship, it is important to forget the pain. Then move on_____ new friendships. May new friendships bring you pleasure and happiness!
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