线路所车站值班员与后方站（线路所）办理区间开通手续前，必须确认（ ）空闲。

The exhaust ports of a diesel engine using the cross-flow scavenging method are opened and closed by the _________.A.reciprocating motion of exhaust valvesB.rotary motion of the camshaftC.reciprocating motion of the pistonD.developed differential

A.
A.reciprocating
B.rotary
C.reciprocating
D.developed

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(题干)奶牛，产后加喂多量精料，随后出现食欲废绝，运动失调，眼结膜充血发绀，中度脱水，瘤胃胀满，冲击式触诊可听到震荡音，排稀软酸臭粪便，尿少色浓，体温正常。该病初步诊断为( )A.瘤胃酸中毒B.前胃弛缓C.奶牛酮酸D.胃肠炎E.生产性瘫痪进一步诊断，最有意义的检测指标是( )A.叩诊瘤胃B.听诊瘤胃蠕动音C.观察反刍和嗳气D.检查肠道和粪便E.测定瘤胃液pH值可能升高的血液指标是( )A.PHB.HCO-3 C.C02??结合力??D.乳酸E.白细胞数请帮忙给出每个问题的正确答案和分析，谢谢！ 点击查看答案