离心泵混流泵及轴流泵的性能参数上各有何特点？

斑疹伤寒立克次体的传播媒介是（）

A.蚊

B.蜱

C.蚤

D.虱

E.螨

线性IgA大疱性皮病的水疱位于（）

A.表皮内

B.表皮下

C.真皮浅层

D.真皮深层

E.皮下

男性，49岁。发热、咳嗽近2周，痰少，色偶黄，伴胸闷。2天来出现咯血就诊，多为满口鲜血，每日约50ml，体检：右上肺叩浊，呼吸音低，闻及湿啰音。胸片示右肺上叶实变伴空洞形成，空洞直径约2.5cm，洞壁光整，未见液平

对本例诊断最简便有用的检验标本是（）。

A.痰

B.防污染样本、毛刷采样标本

C.经气管吸引标本

D.支气管肺泡灌洗液

E.经支气管肺活检标本

A～H都是初中化学中的常见物质，它们之间的转化关系如图所示。A是最简单的有机物，E是一种常见的食品干燥剂。请回答：

(1)A的化学式为                       ；

(2)反应③的基本反应类型是                       ；

(3)反应②的化学方程式为___________________；反应④的化学方程式为____________________。

They are the sort of friends who are so close they trust each other with their lives.If one falls, the other is there to catch him.

They are Wellman, whose legs were permanently injured nine years ago in a rock-climbing accident and Corbett, an experienced rock climber. Together, they climbed up Half Dome. the famous 2,000-foot rock in the Yosemite National park, through one of the most difficult routes(路线).

During the climb, Corbett took the lead, hit in the metal spikes (尖状物)that guided the ropes and climbed up. Then, after Wellman pulled himself  up the rope, Corbett went down to remove the spikes and climbed up again. This process was repeated time and again, inch by inch, for 13 days Wellman’s job was not easy either.  He got himself up the rope through upper body strength alone. In all, Wellman figured(计算) that he had done 5.000 pull-ups up the rope on the climb.

However, when the two men first met, they never talked about climbing. “He knew that was how I got injured.”Wellman said. Until one day Wellman decided that be wanted to climb again and they started training

Their climb of Half Dome was not all smooth. At one point, pieces of rock gave way, and Corbett dropped down quickly. Wellman locked their rope in place, stopping the fall at 20 feet. His quick action probably saved his friend’s life.

“Your partner can save your life—you can sane your partner’s life” Wellman said as the pair received congratulations from friends “there are real close tic.”

小题1:Which of the following was a challenge for Corbett in climbing Half Dome?

A．To climb up to remove the spikes.

B．To climb it twice.

C．To do 5,000 pall-ups up the rope.

D．To lock the rope in place.小题2:Why did the two men never talk about climbing when they first met?

A．climbed was poorly trained.

B．Wellman had lost interest in climbing.

C．Corbett didn’t want to hurt Wellman.

D．Wellman hadn’t decided whether to climb again.小题3:What do we know about Wellman?

A．He climbed Half Dome by himself.

B．He was disabled in a traffic accident.

C．He stopped rock-climbing for some time.

D．He was saved by Corbett during the climb.小题4:The main idea of the text is that.

A．two heads are better than one.

B．friendship is precious in life

C．the disabled should never give up.

D．a man can be destroyed but cannot be defeated.