似蚓蛔线虫幼虫对人的危害主要是
A．肺部损伤
B．消化道症状
C．肝炎
D．并发症
E．血管炎
参考答案：A
You _____ play with fire, Tom. It's dangerous. [ ]
A. needn't
B. may not
C. mustn't
D. wouldn't
试述瓦斯涌出量的表示方法？
