题目

As we have known, learning strategies are a common topic of language learning. But what are learning strategies? They are the methods that learners choose to learn. Here are several examples of language learning strategies. Guess a new word’s meaning in the sentence. This is a basic language skill for students. There is an example: When you first meet the new English word “insist”, you can guess its meaning in the sentence, “His mother didn’t allow him to go with us, but he insisted on coming with us.”Cooperate with partners. Work with other language learners to improve language sk17．实验室常用MnO2与浓盐酸反应制备Cl2（反应装置如图所示）．（1）制备实验开始时，先检查装置气密性，接下来的操作依次是ACB（填序号）．A．往烧瓶中加入MnO2粉末B．加热C．往烧瓶中加入浓盐酸（2）制备反应会因盐酸浓度下降而停止．为测定反应残余液中盐酸的浓度，探究小组同学提出的下列实验方案：甲方案：与足量AgNO3溶液反应，称量生成的AgCl质量．乙方案：采用酸碱中和滴定法测定．丙方案：与已知量CaCO3（过量）反应，称量剩余的CaCO3质量．丁方案：与足量Zn反应，测量生成的H2体积．继而进行下列判断和实验：①判定甲方案不可行，理由是残余液中的MnCl2也会与AgNO3反应形成沉淀．②进行乙方案实验：准确量取残余清液稀释一定的倍数后作为试样．a．量取试样20.00mL，用0.1000mol•L-1NaOH标准溶液滴定，消耗22.00mL，该次滴定测的试样中盐酸浓度为0.1100mol•L-1；b．平行滴定后获得实验结果．③判断丙方案的实验结果偏小（填“偏大”、“偏小”或“准确”）．[已知：Ksp（CaCO3）=2.8×10-9、Ksp（MnCO3）=2.3×10-11]④进行丁方案实验：装置如右图所示（夹持器具已略去）．（i）使Y形管中的残余清液与锌粒反应的正确操作是将锌粒转移到残留溶液中．（ii）反应完毕，每间隔1分钟读取气体体积、气体体积逐渐减小，直至不变．气体体积逐次减小的原因是气体未冷却到室温（排除仪器和实验操作的影响因素）．