不属红细胞生成减少所致的贫血是()
A.红细胞酶缺陷性贫血
B.营养性巨幼细胞性贫血
C.铁粒幼细胞性贫血
D.骨髓病性贫血
E.恶性贫血
参考答案:A
The new laboratories will be constructed this year, and local firms have been asked to ________ the
work. [ ]
A. assign
B. manufacture
C. provide
D. undertake
凝结水泵空气管的作用?水泵出口管处为什么装一个小空气管?