下列哪种是气体激光器的工作物质() A.原子气体 B.分子气体 C.准分子气

题型:单项选择题

问题:

下列哪种是气体激光器的工作物质()

A.原子气体

B.分子气体

C.准分子气体

D.离子气体

E.以上均是

考点:眼科(医学高级)眼科激光眼科激光题库
题型:单项选择题

出口食用动物饲料:直属检疫局在15个工作日内对申请单位做出审核。《登记备案证》有效期5年,期满前6个月重新提出申请。年审为12.1-1.30。( )

题型:单项选择题

阅读理解。

     Mount Qomolangma is the highest mountain in the world. It is in the Himalayan (喜玛拉雅) Mountains

between Nepal (尼泊尔) and China, and it is 8900 meters high. Sir Edmund Hillary from New Zealand and

Tenzing Norgay from Nepal were the first people ever to climb Mount Everest in 1953. Men from several

different countries climbed it after that.

     Junko Tabei, a Japanese was the first woman to make this difficult climb. A Japanese newspaper-television

company chose the fifteen women from mountaineering clubs to climb Mourn Qomolangma in 1975. The

group climbed for several days. Then there was an accident. The heavy ice and snow hurt ten of the women.

They had to stop climbing. The other five went on climbing.

     Only Ms. Tabei was able to climb the last 70 meters. She was standing on the top of the world. She was

the first woman there. Ms Tabei was 35 years old at the time. She started climbing mountains in 1960. She

still climbs mountains. She is not an ordinary Japanese housewife. Ms. Tabei makes money for her trips by

teaching English and piano to children. She climbs a mountain about every three years. She has climbed some

of the highest mountains in six countries. Finally, she wants to climb the highest mountain in every country in

the world. When she reaches the top of a mountain, she thinks, "I'm glad that I'm at the top."

1. Mount Qomolangma is ______. [ ]

A. an ordinary mountain

B. the highest mountain in the world

C. in the southwest of China

D. close to Nepal

2. The climber from New Zealand first climbed Mount Qomolangma in ______. [ ]

A. 1975

B. 1960

C. 1935

D. 1953

3. What happened to ten of the women climbers on the way to the top of Mount Qomolangma? [ ]

A. They were too tired to climb to it.

B. There was no air for them.

C. The heavy snow stopped them.

D. They were hurt by heavy ice and snow.

4. How many women climbed up to Mount Qomolangma in 1975? [ ]

A. One.

B. Five.

C. Ten.

D. Fifteen.

5. What kind of person is Ms, Tabei? [ ]

A. She's a housewife who has climbed many high mountains in the world.

B. She teaches children English and piano to make money.

C. She's a usual housewife who helps a lot at home.

D. She climbed the highest mountain in the world many times.

题型:单项选择题

关于二度Ⅰ型房室传导阻滞的心电图特征,正确的是()

A.P-R间期进行性缩短

B.R-R间距进行性延长

C.固定的房室3:1传导

D.P-R间期进行性延长,伴QRS波脱漏

E.P-R间期恒定

题型:单项选择题

下列有机物中:A.CH4  B.CH2=CH2  C.CH3CH2OH  D.CH3COOH  E.淀粉 (填序号)

(1)水溶液显酸性的是______.

(2)可用于合成聚乙烯塑料的是______.

(3)通常用于检验碘单质的是______.

题型:单项选择题

生产过程密闭,加强通风,把空气中苯浓度降到国家标准()mg/m3以下。

A、80

B、100

C、50

D、40

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