小细胞低色素性贫血见于（）。
A.缺铁性贫血
B.地中海贫血
C.铁粒幼细胞性贫血
D.再生障碍性贫血
E.急性失血性贫血
参考答案：A, B, C
In some areas, quite a lot of students have to work at a very early age,
as they usually don'thave money ____ go to school. [ ]
A. enough; for
B. enough; to
C. much; couldn' t
D. many; can't
什么是元件？它有什么重大作用？元件可以分为哪三个种类？各有什么特点？
