第5题: [单项选择]The author points out that the Greeks who studies conic section ______. A. were unaware of the value of their studies B. were mathematicians C. resigned D. were interested in navigation 参考答案:A 答案解析:根据文中第二段中第四句话“...without the least suspicion that it might someday be useful,...”,由此可见希腊数学家们在研究“conic
第35题:[多选题] 节流、压井管汇使用叙述正确的是( )。 A. 选用节流管汇、压井管不必考虑预期控制的最高井口压力 B. 选用的节流管汇、压井管汇的额定工作压力应与每次开钻所配置的钻井井口装置工作压力值相同 C. 平行闸板阀是一种截止阀,不能用来泄压或节流 D. 节流管汇控制箱上的套、立压表是二次压力表,不能用普通压力表代替 参考答案:CD