【单选题】以下方法中不属于更正错账的方法有( )。
【简答题】A.pooled B.joined C.taken D.participated
【简答题】Not only the students but also their teacher (have) ________ participated in that football .
【简答题】__________ [A] presented [B] attended [C] joined [D] participated
【简答题】化学实验中常常会出现意外情况,这是提升我们学科素养的良好机会,要根据具体情况区别对待,善于发现和解决问题。例如: (1)用高锰酸钾制氧气时,用排水法收集到的氧气呈红色。原因是__________,相应的改进措施是______________________________。 (2)做细铁丝在氧气中燃烧的实验时,集气瓶底部破裂。原因是_______________,相应的改进措施是_________...
【单选题】There are over 1000 volunteers participated in the activity. 如何修改?
B.
把participated 改成 participating
【简答题】A.devoted B.entered C.absorbed D.participated
【单选题】The directors that participated in the meeting were required to contribute _____suggestions to their colleagues
【简答题】某校化学课外活动小组在探究“二氧化碳真的在任何情况下都不支持燃烧吗?”这一问题时,他们设计了下列实验:①将燃着的镁条放入二氧化碳气体中,发现镁条仍在燃烧,大家十分兴奋。观察生成物,除白色物质外,还有黑色物质。②将弯成螺旋状的细铁丝中插上一支燃着的火柴棒放入二氧化碳中,发现立即熄灭。请根据同学们的实验回答下列问题。 (1)写出镁条在CO 2 中反应的化学方程式__________________; ...