题目

同主族元素形成的同一类型化合物，往往其结构和性质相似。PH4I是一种白色晶体，下列对PH4I的叙述正确的是（    ） A.它是一种共价化合物                       B.它既含离子键又含共价键C.它不可能与NaOH溶液反应              D.它受热时不会分解 答案：解析：PH4I与NH4Cl是同主族元素N和P形成的同一类型化合物，其结构和性质应该类似，既含有离子键又含有极性共价键,是一种离子化合物；能与NaOH溶液反应：PH4I+NaOHNaI+H2O+PH3↑；受热时会分解：PH4IPH3↑+HI↑。 答案：B        Reading to dogs is an unusual way to help children improve their literacy skills（读写能力）. With their shining brown eyes, wagging tails, and unconditional love, dogs can provide the nonjudgmental listeners needed for a beginning reader to gain confidence（自信心）,  according to Intermountain Therapy Animals（ITA）in Salt Lake City. The group says it is the first program in the country to use dogs to help develop literacy in children, with the introduction of Reading Education Assistance Dogs （READ）.        The Salt Lake City Public Library is sold on the idea. “Literacy specialists admit that children who read below the level of their fellow pupils are often afraid of reading aloud in a group, often have lower self-respect, and regard reading as a headache,” said Lisa Myron, manager of the children’s department.        Last November the two groups started “Dog Day Afternoon” in the children’s department of the main library. About 25children attended each of the four Saturday-afternoon classes, reading for half an hour. Those who attended three of the four classes received a “pawgraphed” book at the last class.        The program was so successful that the library plans to repeal it in April, according to Dana Thumpowsky, public relations manager. 59．What is mainly discussed in the text?        A．Children’s reading difficulties.              B．Advantages of raising dogs.        C．Service in public library.        D．A special reading program. 60．Specialists use dogs to listen to children reading because they think__________.        A．dogs are young children’s best friends        B．children can play with dogs while reading        C．dogs can provide encouragement for shy children        D．children and dogs understand each other 61．By saying “The Salt Lake City Public Library is sold on the idea”, the writer means the library ______________.        A．uses dogs to attract children           B．accepts the idea put forward by ITA        C．has opened a children’s department        D．has decided to train some dogs 62．A “pawgraphed” book is most probably _________.        A．a book used in Saturday classes             B．a book written by the children        C．a prize for the children                   D．a gift from parents