A:水
B:有机物
C:无机盐
D:氧气
Forty minutes _______ for the children to finish all the work.
You never feel worried before an exam, how can you? Well, I've been working hard all the time. Surely I am _________ any exam.
将质量相等的铝粉和铁粉分别与同体积、同浓度的稀硫酸反应,反应情况如下图所示。有关叙述中正确的是 ()
将下列陈述句改成疑问句
那是小红。