小红要写一篇有关“蔡侯纸”的历史小论文。她可以查阅司马迁《史记》中的记载。
错误：
理由：
∠A是锐角，且sinA=cosA，则∠A的度数是（ ）
_____ the students came from different countries, they got along quite well in the summer camp.
2PbSO4(s) ＋ 2H2O(l)；下列说法正确的是 ( )