未知题型 Last week when I took a walk down the road at my relatives I was surprised to see many earthworms on the asphalt road. I had walked on this road many times before and never seen the earthworms. Then I recognized that I had never walked just after a heavy rain. So, I suppose that the rain caused the earthworms to come out of the ground. Indicate the causal claim (x causes y - what are the x and y?)

未知题型 某染化车间合成工段液氯钢瓶和管道装置连接处的隔膜阀损坏，氯气泄露，工人张某发现后立即去修理，情急之下未戴防毒面具，吸入大量的氯气后出现皮肤、眼刺激症、咳嗽、胸闷、胸骨后疼痛、呼吸困难等症状，同时多名工人出现刺激反应。针对患者张某的氧疗不恰当的是（）

单项选择题 流行曲线的x轴代表（）