什么是燃气轮机的动叶片?
参考答案:
燃气轮机的动叶片又称工作叶片,安装在叶轮的外圆周上。
—Mr. Green was born in China.
—It’s no _____ he can speak Chinese so well.
matter B. doubt C. wonder D. problem
氧的元素符号是( )
A.C
B.O
C.H
D.Fe