题目

--- Have you thought of the topic for the composition?---Not yet, I _______ it very carefully, but I haven’t decided. A. will considerB. have been considering C. had considered D. was considering 答案：B 解析: I haven’t decided yet说明一直在考虑，还没决定，故选B。写出下列反应的化学方程式，并在括号里注明反应的基本类型：（1）一氧化碳燃烧______ 2CO2