甲烷化反应器氮气升温结束，准备开车时，氮气软管如不脱除，氢气会窜入软管发生事故。
参考答案：对
男，26岁，进行性鼻腔阻塞、流涕来院就诊，近两年持续性头痛、头晕.如图所示筛窦区占位灶应诊断为（）
A.脊索瘤伴左上颌窦炎
B.软骨瘤伴左上颌窦炎
C.骨化性纤维瘤伴左上颌窦炎
D.骨结核伴左上颌窦炎
E.骨纤维异常增殖症伴左上颌窦炎
— Where was your brother at this time last night— He was writing an e-mail ______ I was watching TV at home.
A. as soon asB. afterC. untilD. while
