女性，20岁。反复发作呼吸困难、胸闷、咳嗽3年，每年秋季发作，可自行缓解，此次已发作半天症状仍继续加重而来就诊。体检：双肺满布哮鸣音，心率90次/分，律齐，无杂音。4．[假设信息]应用足量解痉平喘药和糖皮质激素等治疗均无效，患者呼吸浅快、神志不清，PaO26．7kPa(50mmHg)，PaC．2>9．3kPs(70mmHg)。此时应采取的救治措施为

A．高浓度吸氧

B．甲基泼尼松龙静脉滴注

C．纠正水电解质和酸碱平衡素乱

D．联合应用广谱抗生素静滴

E．气管插管正压机械通气

Passage One

What was one result of the increased use of machinery on farms of the United States a. Prices for farm produce rose. b. Farmers became more dependent on loans from banks. c. Jefferson established government programs to assist farmers. d. Farmers relied less on foreign markets.