室内空气污染物中哪个与肺癌发病密切()
A.甲醛
B.SO2
C.NOX
D.222Rn
E.CO
参考答案:D
My classmates were playing happily _____ I got to the park. [ ]
A. when
B. before
C. after
CT脊髓造影显示神经根袖闭塞,硬膜囊变窄不规则,最大的可能是()
A.星形细胞瘤
B.先天变异
C.蛛网膜炎
D.神经纤维瘤病
E.先天性硬膜囊变窄