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在25℃时，密闭容器中X、Y、Z三种气体的初始浓度和平衡浓度如下表： 物质XYZ 初始浓度(mol·L－1)0.10.20 平衡浓度(mol·L－1)0.050.050.1 下列说法错误的是( ) A．反应达平衡时，X的转化率为50% B．反应可表示为：X＋3Y2Z，其平衡常数为1600 C．增大压强使平衡向生成Z的方向移动，平衡常数增大 D．改变温度可以改变此反应的平衡常数STUDY BOOKSBasic Study Manual: $30Future success depends on the ability to learn. Here are the answers to the questions most often asked by parents, teachers, business trainers and by students themselves. Read this book and learn:★What the three barriers (障碍) to study are and what to do about them.★What to do if you get tired of a subject you are studying.Twenty-six simple drills to help you learn how to study easily, rapidly and with full understanding.Buy and read the Basic Study Manual and use it to dramatically improve your ability to study.Study Skills for Life: $20L. Ron Hubbard’s study technology for teenagers opens the door to their future success by giving them the ability to study and learn. Fully illustrated (插图) for easy understanding.Learning How to Learn: $40The basics of effe ctive study for 8 to 12-year-olds, fully illustrated. Children who read and apply the materials in this book regain their liking for study and their ability to apply this knowledge in life. Get this book for a child you want to see win at his studies! Buy it before May 1, 2005, and you’ll just pay half less.How to Use a Dictionary Picture Book for Children: $40In spite of billions of dollars spent on “educational research”, children are not taught the most basic skills of learning, even the most basic of these: how to use a dictionary. Written for children from 8 to 12-year-olds, this fully illustrated book will teach your child:★How to find words in a dictionary★The different ways that words are used★What the different marks and symbols that are used in a dictionary mean★How to use a dictionary to correctly pronounce wordsIt includes a section for parents and teachers showing you how to use this book with children. Buy this book and give it to your children to unlock their education. What’s more, you’ll just pay 50% for it before May 1, 2005. 49．From the reading we know that all the four books are intended for________.A. teachers                  B. adults                       C. children                   D. women50．Some of the four books were illustrated in order to________.A. help readers understand them betterB. persuade more readers to buy themC. reduce the cost of them D. make them suitable for different readers51．If you buy all the four books in April, 2005, you will have to pay______ for them.A. $65                        B. $80                          C. $90                         D. $13052．The purpose of the passage is to________.A. introduce the four books to readersB. help children to learn EnglishC. make students know the importance of learningD. sell the four books to students