高压加热器正常运行时，加热器疏水温度约高于给水进口温度（）℃。
参考答案：5.6～11
The doctor had almost lost hope at one point, but the patient finally ________ .[ ]
A ．pulled through
B ．pulled out
C ．pulled up
D ．pulled over
简述碳元素在钢中的含量及其对钢的性能产生影响？
