A：Fe2+ + Cl2 → Fe3+ + 2Cl—
B：4FeS2 + 11O2 → 2Fe2O3 + 8SO2
C：NH3 + H2SO4 → （NH4）2SO4
D：Al3+ + 6OH— → AlO2— + 3H2O
—Did you have fun _____________ on your last day off?
—No, I didn't. there were too many people and it was really crowded.
按课文《朱德的扁担》内容填空。
朱德同志也跟战士们____。他穿着____，戴着____，挑起____，跟大家____。大家劝他不要挑，他____。有个同志就把他那根____。不料，朱德同志连夜又____，并写上“____”三个字。大家见了，越发____，不好意思再____。
