题目

一包由CuSO4、CaCO3、BaCl2、Na2SO4、NaOH中的两种或两种以上的物质混合而成。取少量白色粉末，向其中加入足量的水，充分搅拌后过滤，得到白色沉淀和无色滤液X。在滤出的白色沉淀中加入足量的盐酸，沉淀全部溶解，并产生无色气体。下列判断错误的是 A．原白色粉末的组成有3组可能 B．原白色粉末中一定含有CaCO3 C．原白色粉末中一定不含有CuSO4 D．若向无色滤液X中通入二氧化碳，产生白色沉淀，则可推断原白色粉末中一定还含有BaCl2、NaOHThe creative projects of World Food Program (WFP) focused on preventing hunger from taking hold in the future and breaking the cycle of hunger. Here are some of the ways in which we work to prevent hunger in the future:School MealsAs well as directly addressing hunger, School Meals projects encourage families to keep their children in school and help them build better futures. If children aren’t hungry they will concentrate on their lessons. With a solid education growing children have a better chance of finding their own way out of hunger. These projects benefit girls especially. For more information: www.wfp.org/schools meals.Food for Assets（有用的人）WFP’s Food for Assets projects provide the hungry with food to lay the foundation for a better tomorrow. When poor farmers no longer have to worry about the next meal, they have the time and energy to build irrigation（灌溉） systems that can increase production. Similarly, Food for Training projects allow the poor to devote time to learning skills that will sustain（维持） them economically in the future. For more information: www.wfp.org/food-assets.HIV/AIDSWFP uses its food rations(配给) to reduce the blow of HIV and AIDS. The agency distributes its rations to people living with HIV and AIDS, so they can keep providing for their families for longer and have time to transfer vital knowledge and skills to the growing number of AIDS children--the next generation of food providers in developing countries. For more information: www.wfp.org/hiv-aids.Purchase for ProgressWFP buys large amounts of food in developing countries. It has this purchasing power and uses it to help poor farmers contact reliable markets where they can get competitive prices for their produce. With secure markets, farmers will be encouraged to produce more and innovate(创新).The knock-on effect (连锁效应) is producing more food for everyone. For more information: www.wfp.org/purchase-progress.1.The text is written with the purpose of ____.A. seeking solutions to some hot issuesB. introducing some of WFP’s projectsC. raising money for the people in needD. calling readers’ attention to the poor2.The farmers who want to receive some training should visit_____.A. www.wfp.org/food-assetsB. www.wfp.org/hiv-aidsC.www.wfp.org/purchase-progressD.www.wfp.org/school-meals3.AIDS children can benefit from food rations in that（在于，因为）_____.A. they no longer go hungryB. they can take care of their parentsC. they don’t have to worry about foodD. they can learn more skills from their parents4.By buying large amounts of food in developing countries, WFP aims to ____.A. help farmers to increase their incomeB. introduce new ways of farming to farmersC. encourage farmers to produce more foodD. motive farmers to plant different kinds of crops.