倘若煤气的（）和化学能得到充分利用，高炉燃料消耗就降低。

男，55岁，肝区持续性疼痛半年，伴乏力，消瘦明显，食欲减退，恶心，低脏，质硬，收入院。

下列哪一项检查有确诊意义（）.

A.肝穿刺细胞学检查

B.X线钡餐检查

C.B超检查

D.CT检查

E.放射性核素肝扫描

When my first wartime Christmas came, I was in basic training in New Jersey and not sure if I would make it home for the holidays. Only on the afternoon of December 23 was the list of men who would have the three-day holiday posted. I was one of the lucky soldiers. It was Christmas Eve when I arrived home, and a little snow had fallen. Mother opened the front door. I could see beyond her, into the corner of the living room where the tree had always stood. There were lights, all colors, and ornaments (饰品) shining against the green of a pine.

"Where did it come from?" I asked.

"I asked the Gates boy to cut it," my mother said. "I wouldn't have had one just for myself, but when in great need... such a rush! He just brought it in this afternoon."

The pine reached to the proper height, almost to the ceiling, and the Tree Top Crystal（水晶） Star was in its place. A few green branches reached out a little awkwardly（难看） at the side, I thought, and there was a bit of bare trunk showing in the middle. But the tree filled the room with warm light and the whole house with the pleasant smell of Christmas.

"It's not like the one you used to find," my mother went on. "Yours were always in good shape. I suppose the Gates boy didn't know where to look for a better one. But I couldn't be fussy(挑剔的)."

"Don't worry," I told her. "It's perfect."

It wasn't, of course, but at the moment I realized something for the first time: All Christmas trees are perfect.

小题1:What did his mother's Christmas tree look like?

小题2:From the passage we can infer (推断) that______.

A．all the soldiers had the three-day holiday

B．the writer could not go home for Christmas

C．the writer spent his first Christmas during the war

D．not all the soldiers went home for Christmas during the war小题3:From the passage, we can conclude that ______ .

A．his mother didn't like Christmas trees

B．the writer didn't like the tree cut by someone else

C．the writer used to cut very beautiful Christmas trees

D．his mother didn't want to have a Christmas tree during wartime小题4:The best title for this passage would be ______.

A．The Perfect Christmas Tree

B．How to Choose a Christmas Tree

C．How Soldiers Spent Their Christmas

D．A Christmas with an Ugly Christmas Tree小题5:What does the writer mean by saying “All Christmas trees are perfect”?

A．Nothing is as perfect as Christmas.

B．Once at home, everything is so nice.

C．During the war, trees are hard to find.

D．All Christmas trees are the most beautiful.

形成周期性的原因主要有（）

A.传播机制容易实现

B.新生儿的增加

C.病原体的变异及变异的速度

D.病后可形成较为牢固的免疫力

E.虫媒昆虫生态习性

（）是将可能妨碍故障判断的硬件或软件屏蔽起来的一种判断方法。

A、观察法

B、最小系统法

C、隔离法

D、替换法

在卧式镗床上加工指教矩形槽时，镗床主轴轴线应与直角矩形槽（）。

A.相平行

B.倾斜一个角度

C.向垂直