题目

下列离子方程式书写正确的是( ) A．用Pt电极电解少量的MgCl2溶液：2H2O＋2Cl－H2↑＋Cl2↑＋2OH－ B．向氢氧化亚铁中加入足量的稀硝酸：Fe(OH)2＋2H＋===Fe2＋＋2H2O C．向NaAlO2溶液中通入过量CO2制Al(OH)3：AlO＋CO2＋2H2O===Al(OH)3↓＋HCO D．用食醋除去水瓶中的水垢：CO＋2CH3COOH===2CH3COO－＋CO2↑＋H2O 答案：解析 电解氯化镁溶液应生成Mg(OH)2沉淀，A项错误；稀硝酸能够氧化Fe2＋，B项错误；水垢的主要成分为CaCO3，应写化学式，D项错误。 答案 C读下面短文，从短文后各题所给的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项。As we know, it is important to be honest with children. But there are some things in this world that simply aren’t_________. Sometimes it makes sense for parents to_________to their children.I still remember my three-year-old daughter’s face when we watched the_________that twenty children at Sandy Hook Elementary School had been killed. After a few minutes she_________and put her_________arms around my legs and said, “I love you, Momma.” I was still _________ whether or not to turn the TV off when she, _________, asked, “Momma, why aren’t those kids OK?” I just _________ that they were smart children, _________they did something wrong and got punished.We’re not all_________of a little lie here and there. Santa Claus, the Easter Bunny and Snow White are just a few examples of_________for parents to keep magic in the world. Magic, imagination and creativity are very essential in life, _________ for children. These stories battle against the negative aspects of the world and create _________ . In the end children will be able to_________ what is true and what was made to_________their lives. Out of five brothers and a sister I can happily report that not one of the children I grew up with was _________when we discovered who all those _________people really were.In life, a parent is the _________of knowledge, and it is up to the parent to decide what knowledge to teach and when. There’s no_________ to tell children all about the truth. As they become_________ , they will have a better understanding of the world.1.A. user-friendly B. kid-friendly C. reader-friendly D. teacher-friendly2.A. agree B. talk C. lie D. react3.A. news B. game C. discussion D. experiment4.A. came out B. fell down C. called back D. reached up5.A. long B. little C. thin D. strong6.A. arguing B. researching C. considering D. questioning7.A. in peace B. in danger C. in doubt D. in puzzlement8.A. explained B. announced C. suggested D. apologized9.A. so B. but C. or D. until10.A. afraid B. tired C. guilty D. nervous11.A. activities B. goals C. possibilities D. ways12.A. especially B. probably C. gradually D. frequently13.A. luck B. hope C. honor D. wealth14.A. describe B. predict C. understand D. remember15.A. save B. live C. start D. better16.A. excited B. upset C. special D. curious17.A. imaginary B. homeless C. strange D. generous18.A. friend B. partner C. keeper D. advisor19.A. time B. choice C. risk D. need20.A. older B. cleverer C. braver D. busier