如果W代表混合物的喷出速度,U代表火焰传播速度,那么脱火的条件是(),回火产生的条件

题型:填空题

问题:

如果W代表混合物的喷出速度,U代表火焰传播速度,那么脱火的条件是(),回火产生的条件是(),正常燃烧的条件是()。

考点:加热工考试加热烧火工加热烧火工题库
题型:填空题

2009年甲型H1N1流感在墨西哥暴发并在全球蔓延,至今影响重大。我们应通过注意个人卫生加强防范。研究表明,甲型H1N1流感球形病毒细胞的直径约为0.00000156m,用科学记数法表示这个数是[ ]

A.0.156×10-5 m

B.0.156×105 m

C.1.56×10-6 m

D.1.56×106 m

题型:填空题

If there were no examinations, we should have _______ at school.             [ ]

A. the happiest time    

B.a more happiest time            

C. much happiest time    

D.a much happier time

题型:填空题

阅读理解。

1. What will I need to take a Test?

     You need a photo ID, your instructor's name, a pencil or pen, a calculator, etc.

2. How will I know about time limits?

     Students will be informed of any testing time limits, and notified when time is up.

3. If I have my books or backpack, does the Test Center have a place to store them while I'm

testing?

     Yes. Students will be asked to leave all books, backpacks, purses and any other personal items in a

lockable storage room.

4. The only time I can take a test is during lunch. Can I eat my lunch while I am testing?

     No food or drink are allowed in the Test Center.

5. I conduct business via a pager(寻呼机) or cell phone. Will I be allowed to use them in the

Test Center?

     No. all pagers and cell phones must be turned off before entering the Test Center. There are other

students testing who may be distracted by these devices.

6. If I need to borrow more scratch paper(草稿纸) am I allowed to borrow from another student

in the Test Center?

     Ask the teacher and more material will be given. Talking is not permitted in the Test Center. You will

give all scratch paper to the teacher at the end of the test.

7. If I start a test but don't finish it, can I come back the next day to finish it?

     If you have prior(在先的) arrangements with your instructor you may continue a test the next day.

Students are expected to complete their test before closing time of the Test Center. Depending on the

test, most tests will not be given within one hour of closing time.

1. When you take a test in the Test Center, all of the following are forbidden EXCEPT _____.

A. to eat and drink                       

B. to use your cell phone

C. to leave your purse on the desk            

D. to ask for more scratch paper

2. If you don't finish the test you ______.

A. must turn in the paper on time  

B. should get help from your instructor

C. can continue it the next day by prior arrangement

D. can take the paper out of the center

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

A. Frequently asked questions about the Test Center

B. Useful suggestions on different kinds of tests

C. General requirements for students to have tests

D. Brief introduction to the Test Center

题型:填空题

饮用水深度净化的目的是()

A.去除水中的病原体 

B.去除水中的有机物 

C.去除水中的化学物质 

D.去除水中的低分子盐类 

E.获得优质饮用水 

题型:填空题

某公司现借款1000万元,一年后付息80万元,则年利率为( )。

A.0.8%
B.8%
C.80%
D.81%

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