氢气纯度降低是造成甲烷化反应器床层温度升高的原因之一。
参考答案：对
---If there are _______ people driving, there will be _______ air pollution.
---Yes, the air will be fresher.
A．less; less
B．less; fewer
C．few; fewer
D．fewer; less
流行性出血热的典型症状“三痛”是指（）
A.头痛、腰痛、四肢痛
B.头痛、腰痛、肌肉酸痛
C.头痛、腰痛、眼眶痛
D.头痛、腰痛、腓肠肌痛
E.腰痛、腓肠肌痛、眼眶痛
