夜间在海上从事捕鱼作业的船舶.应显示舷灯,尾灯的情况是:().Ⅰ在航对水移动Ⅱ、在航

题型:单项选择题

问题:

夜间在海上从事捕鱼作业的船舶.应显示舷灯,尾灯的情况是:().Ⅰ在航对水移动Ⅱ、在航不对水移动Ⅲ、锚泊时

A.Ⅰ、Ⅱ、Ⅲ

B.Ⅰ、Ⅱ

C.Ⅰ

D.Ⅱ、Ⅲ

考点:海船船员考试船舶管理(大副)船舶管理(大副)题库
题型:单项选择题

在一定条件下,萘可以被硝硫混酸硝化生成二硝基物,它是1.5-二硝基萘(

)和1.8-二硝基萘(

)的混合物.后者可溶于质量分数大于98%的硫酸,而前者不能.利用这个性质可以将这两种异构体分离.将上述硝化产物放入适量的98%硫酸,充分搅拌,用耐酸漏斗过滤,欲从滤液中得到固体1.8-二硝基萘,应彩的方法是(  )

A.蒸发浓缩结晶

B.向滤液中加入水后过滤

C.用Na2CO3溶液处理滤液

D.将滤液缓缓加入水中过滤

题型:单项选择题

阅读理解。

     We tried so hard to make things better for our kids that we made them worse. For my grandchildren, I'd know better. I'd really like for them to know about hand-me-down clothes and home-made ice cream and leftover meatloaf. I really would.

     My cherished boys, I hope you learn humility by surviving failure and that you learn to be honest even

when no one is looking. I hope you get a black eye fighting for something you believe in. I hope you have

to share a bedroom with your younger brother. And it is all right to draw a line down the middle of the

room, but when he wants to crawl under the covers with you because he's scared, I hope you'll let him.

And when you want to see a Disney movie and your kid brother wants to tag along, I hope you take him.

     I hope you have to walk uphill with your friends and that you live in a town where you can do it safely.

I hope you learn to dig in the dirt and read books, and when you learn to use computers, you also learn

how to add and subtract in your head.

     May you skin your knee climbing a mountain, burn your hand on the stove and stick your tongue on a

frozen flagpole (旗杆). I hope you get sick when someone blows smoke in your face. I don't care if you

try beer once, but I hope you won't like it.

     I sure hope you make time to sit on a porch with your grandpa or go fishing with your uncle.

     I hope your mother punishes you when you throw a baseball through a neighbor's window, and that

she hugs you and kisses you when you give her a plaster of pared mold of your hand.

     These things I wish for you-tough times and disappointment, hard work and happiness.

1. Who wrote the letter? 

A. A grandmother.      

B. A grandfather.      

C. A father.        

D. A mother.        

2. What does the author hope for the boys?  

A. they learn a lesson from a fight with others.

B. they know how to calculate with computers.

C. they have a close relationship with one another.

D. they burn their hand on the stove and stick their tongue on a frozen flagpole.

3. Why does the author write the letter?

A. To show the boys it's not easy growing up.

B. To teach the boys dos and don'ts on the way growing up.

C. To help the boys to avoid making mistakes on the way growing up.

D. To encourage the boys to fully experience life on the way growing up.

题型:单项选择题

直肠齿状线上5cm处癌肿,无梗阻。导致持续性疼痛的原因是()

A.近端肠管扩张

B.癌肿侵犯骶前神经丛

C.癌肿侵犯直肠黏膜神经

D.继发感染

题型:单项选择题

硫脲类抗甲状腺药物的主要作用是()

A.使体内甲状腺激素作用减弱

B.抑制碘的吸收

C.抑制甲状腺激素合成

D.抑制甲状腺激素的释放

E.抑制促甲状腺激素的作用

题型:单项选择题

直流斩波器可以把直流电源的可调电压变为固定的直流电压输出

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