题目

Only _______ students are in the classroom after class. Most students go to the playground to do sports. A . a few B . a little C . many D . much 答案：A实验室制取CO2一般有五个步骤：①检查装置的气密性；②按要求装配好仪器；③向漏斗中注入酸液；④向广口瓶放人小块的大理石；⑤收集气体。下列操作顺序中，正确的是 (   ) A．①②③④⑤   B．②①④③⑤   C．①④②③⑤   D．②③④①⑤