A：人们买衣服要凭布票而且数量有限
B：发色彩和样式也很单调
C：人们都穿着千篇一律的灰色中山装或兰色解放装
D：时装表演成为一道靓丽的风景线
用氢气、氧气、氮气、水蒸气、二氧化碳五种气体的化学式填空：
4的平方根是（ ）
---Do you know Tan Dun?
---Of course. He is a famous composer and won ______Oscar for his music in the film Crouching Tiger, Hidden Dragon in 2001.
下列运算中，正确的是
