题目

下列实验操作正确的是（ ） A． A．点燃酒精灯           B． B．往试管中加入锌粒  C． C．称量氢氧化钠    D． D．收集氧气 答案：【分析】A、据点燃酒精灯的方法分析； B、据块状药品取用的方法分析； C、据称量固体药品的方法和注意事项分析； D、据氧气的收集方法分析． 【解答】解：A、应用火柴点燃酒精灯，不能用燃着的酒精灯去引燃另一酒精灯，这样容易引发火灾，故错误； B、块状药品的取用方法是“一横二放三慢竖短文改错假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。增加：在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。删除：把多余的词用斜线(划掉。修改：在错的词下划一横线，并在该词下面写出修改后的词。注意：1. 每处错误及其修改均仅限一词；2. 只允许修改10处，多者(从第11处起)不计分。In the future，schools will be different in many ways from which they are now. First，students will be different. They will be any age，from any place，and they will be free to choose any class we want. They will all get along and make friends easy. Second，the courses will be different. There will be many more courses for students to choose，and most courses will be offer on the Internet. Students will choose to learn at home on the Internet， and at school from teachers. They can also choose the teachers they like.School buildings and equipments will be much better as they are now. Everything will be run by computers， more modern，and easy for students to use.Students will organize more different activities at school，and life at school will be richer and more interesting.In a conclusion，future schools will be better learn places for students.