机械密封的密封环平面度要求在0.0009mm以内。

“一粒沙子是松散的，可是它和水泥、石子、水混合后，比花岗岩还坚韧。”这句话揭示的是  [ ]

A、混凝土是优良的建筑材料

B、个人只有融入集体才有力量

C、集体与个人相互依存

D、集体的力量大于个人的力量

.

Nate suffered a hard blow when he lost his job．His boss had spoken rudely, “Your services are no longer needed.” Nate left the building filled with despair．By the time he reached home, he was in a deep depression．When he entered his house, he blurted out to his wife Sophia, “I lost my job．I am a complete, utter failure.” A tense silence followed．Then a smile crept across Sophia’s face．“What great news!” she responded.

“Now you can write the book you have always wanted to write.”

“But I have no job and no prospect of a job,” YC he objected, completely without hope．“If I struggle to be an author, then what will we live on? Where will the money come from?” Sophia took her husband by the hand and led him to the kitchen．Opening a drawer, she took out a box that was full of cash．“Where on earth did you get this?” Nate gasped．“To whom does it belong?”

“It’s ours!” Sophia replied．“I always knew that one day you would become a great writer if only you were given the chance．From the money you gave me for housekeeping every week, I have saved as much as I could so you would have your chance．Now there is enough to last us a whole year.”

What a surprise! What encouragement! What a wife! The unemployed husband did concentrate on writing that year, and the novel he wrote became a literary masterpiece．The book is The Scarlet Letter．Sophia had an even greater achievement, and she turned Nathaniel Hawthorne from a poor clerk into a world famous master．  

68．Which of the following can be inferred from the first paragraph?

A．Sophia was very disappointed to hear the news  

B．Nate was too sad to speak any more

C．Sophia was thinking of how to encourage Nate  

D．Neither husband nor wife had any idea what to do

69．Sophia saved money because _______________________．

A．she knew her husband would lose his job one day  

B．she knew their life would be in difficulty

C．she was very careful with money  

D．she was trying to help her husband in every possible way

70．From the passage we can know that Sophia was __________________________．

A．kind and brave        B．careful and encouraging

C．friendly and warm-hearted      D．honest and determined

71．What would be the best title for the passage?

A．Sophia’s Achievement    B．A Great Writer’s Struggle to Success

C．Great Encouragement in Hard Times     D．Failure is the Mother of Success

男性，25岁，主诉心前区疼痛2小时，向左肩放射，吸气时疼痛加重，坐位时减轻，伴有畏寒、发热就诊，体检：血压105／75mmHg，体温38℃，心率110次／分，规则，心脏无杂音，两肺未见异常，有血吸虫病史。心电图示除aVR与V外各导联ST段抬高。

此时作X线检查可能显示（）。

A.左肺野楔状实质性阴影，伴左胸腔积液

B.正常

C.肺部无明显充血而心影显著增大

D.左肺野多发炎症阴影

E.两侧肺门影不大

呼吸衰竭时缺氧与二氧化碳潴留的发病原理为（）

A.通气／血流比例（V／Q）失调

B.弥散功能障碍

C.肺泡通气不足

D.血液循环障碍

E.呼吸频率改变

在使用电流、电压表及钳形电流表的过程中，都应该从最大量程开始，逐渐变换成合适的量程。