架空热力管道在不妨碍交通的地段采用（）敷设。
A、低支架
B、中支架
C、高支架
参考答案：A
It suddenly occurred to him he had left his keys in the office.
A．whether
B．where
C．which
D．that
周围血中网织红细胞增多最常见于（）
A.未经治疗的缺铁性贫血
B.溶血性贫血
C.淋巴瘤
D.巨幼细胞性贫血
E.再生障碍性贫血
