下列实验操作能达到目的是( ) A.乙烷(乙烯),将混合气体通过盛有酸性KMnO

题型:选择题

问题:

下列实验操作能达到目的是(  )

A.乙烷(乙烯),将混合气体通过盛有酸性KMnO4溶液的洗瓶,再用排气法收集

B.向蔗糖水解后的液体中加入新制Cu(OH)2悬浊液,加热到沸腾,验证水解产物为葡萄糖

C.通过灼烧的方法判断蚕织品和棉织品

D.用NaOH溶液除去CH3COOCH2CH3中少量CH3COOH

考点:物质的除杂设计实验方案及探究实验
题型:选择题

It’s not easy to be an astronaut’s son. Everybody expects you to be special or perfect. I often wonder how my father ever had a son like me. I mean he’s so special and so good at everything he does. Even in middle school he was class president and captain of the football team.
Well, to be honest, I often dream about being some kind of hero or doing something special-like saving a child from a burning building or discovering a new star. I was daydreaming at school one morning when my teacher said there would be a Father’s Day writing competition for the whole school. "I hope we have a winner right here in my class. "
When I got home, I started to think about what to write. My father is an astronaut. No, I wouldn’t start like that. That was the way others saw him. How did I see my father Hmm.
I saw him sitting with me in the dark when I had a terrible dream. I remembered how he hugged me for hours when my dog Spotty was killed by a car. Yes, these were the things I was going to write. To me, he wasn’t just a world-famous astronaut. He was my dad.
My parents and I went to school Thursday night. There were so many people in the big hall! My dad looked at me, and I shrugged (耸肩).
The third prize was announced and it was not me. I was relieved (释然) and disappointed at the same time. The second prize was announced. It was me.
I went up to the stage and read what I had written, My Father’s Son. When I finished, the people stood up and cheered. I saw my father blowing his nose. Tears were running down my mother’s face. Dad cleared his throat and put his hand on my shoulder. "Son, this is the proudest moment of my life. "
It was the proudest moment of my life, too. Maybe I’ll never be a great hero or win a Nobel Prize, but it was enough just to be my father’s son.

The writer felt it ______ to be the son of a famous person.

A. lucky

B. natural

C. hard

D. pleasant

题型:选择题

各种勤务车辆停靠飞机是否需要有专人指挥()。

A.不需要

B.需要

C.司机慢悠悠开

D.司机能看清停靠飞机位置即可

题型:选择题

患儿,1岁。发热、咳嗽、流涕3天入院。入院后体温持续不退,达40℃,呕吐、谵妄,抽搐2次。体检:胸、腹部及四肢皮肤有瘀斑,前囟隆起,双肺呼吸音粗糙,可闻及少许干性啰音,腹软,脑脊液外观浑浊。

为明确病原菌,应首先进行的检查是()。

A.神经传导功能测定

B.痰液涂片

C.胸部X线片

D.脑电图检查

E.皮肤瘀斑涂片找细菌

题型:选择题

我国人口与一些资源之间的矛盾,表现在

A.环境污染和生态退化

B.耕地总数和人均可耕地存在继续减少的趋势

C.自然环境的承载能力已达极值

D.河流径流量丰富,资源利用水平高

题型:选择题

OTDR在设置测量参数时,应根据()来设置光纤折射率,不同厂家生产出的光纤折射率存在差别。

更多题库