汽轮机启动停机和变工况过程中,高压缸的调节级、再热机组中压的()区等处的蒸汽温度变化大,热交换(),金属部件内引起的温差大。
参考答案:进汽;剧烈
Jill and Katy ________ with their class tomorrow. [ ]
A. are going to hiking
B. are going hiking
C. go to hiking
Wigand术式程序的第一步是()
A.切除钩突
B.开放筛泡
C.切除中鼻甲基板
D.切除中鼻甲后部
E.开放蝶窦