控制液油压只许按一方向流动,不能反向流动的方向阀叫()。
参考答案:单向阀
小儿时期常见的贫血是
A.大细胞性贫血
B.正细胞性贫血
C.营养性缺铁性贫血
D.营养性巨幼细胞贫血
E.再生障碍性贫血
It was in the garden of his old house _____ he grew up that he dug up a pot of gold. [ ]
A. that
B. where
C. which
D. what