_____ we got to the station, the train had left already.
A.If
B.Unless
C.Since
D.When
答案:D
素描画纸的纸面应()。
A.细腻
B.平滑
C.略细
D.略粗
有确诊意义的检查是
A.血培养B.脑脊液检查C.特异性IgM抗体检测D.骨髓穿刺涂片检查E.肝、肾功能检查