调节级
参考答案：外界负荷变化时，依靠依次启闭的调节阀改变汽轮机第一级的通流面积来改变机组负荷的级。
黄芪在当归补血汤中的作用是____；在固冲汤中的作用是____。
In heavy seas you decide to heave to. The lifeboat should be（）.
A.brought to a position with the stern into the seas
B.allowed to take its own head
C.brought to lay in the trough
D.brought bow into the seas
