烧嘴有哪几路冷却水？
参考答案：
烧嘴冷却水包括：外夹套冷却水主要冷却粉煤通道、中夹套冷却水主要冷却氧通道、内夹套冷却水主要冷却开工和点火烧嘴通道。
乳酸在医药、食品等工业中应用前景广阔，近年来，乳酸成为人们研究的热点之一．乳酸的化学式为C3H6O3，试计算：
（1）乳酸中碳、氢、氧元素的质量比；
（2）乳酸中碳元素的质量分数．
A 13-year-old visits the school nurse because he’s experiencing back pain, fatigue, and dyspnea. The nurse suspects that the child may have scoliosis. The nurse should first（）
A. send the child home to recover.
B. inspect the child for uneven shoulder height or uneven hip height.
C. arrange for the child to have spinal X-rays as soon as possible.
D. ask the child’s parent to take him to a physician immediately.
