酸性焊条的药皮中含有较多的二氧化硅、氧化铁及氧化钛,氧化性较强,焊缝金属中的氧含量较

题型:单项选择题

问题:

酸性焊条的药皮中含有较多的二氧化硅、氧化铁及氧化钛,氧化性较强,焊缝金属中的氧含量较高,合金元素烧损较多,合金过渡系数较小,熔敷金属中含氢量也较高,因而焊缝金属的塑性和韧性()。

A.较高

B.较低

考点:建设工程技术与计量(安装工程)第一节切割和焊接第一节切割和焊接题库
题型:单项选择题

喷射浮选机属于()浮选机。

A.充气式 

B.气体析出式 

C.自吸式 

D.压气式

题型:单项选择题

人体非特异性免疫功能:()

A.细胞免疫

B.体液免疫

C.两者均有

D.两者均无

题型:单项选择题

Top lists are lecturing people on everything from"100 books to visit " to "100 books to read ".

Aren't you just tired of being told what to do with your time?

Now you have a list to end all lists!

Take a look at the following two examples from the list of "101 things not to do":

Swim with Dolphins(海豚)?

Swimming with dolphins is one of the world’s most profitable tourist activities. However, every dolphin will welcome having their busy, tiring day interrupted by tourists screaming and pushing around them in the water. Worse yet, when dolphins get too near to the boats loaded tourists, they could get caught up in ropes and killed by propellers(螺旋桨).

Here’s a little secret. Dolphins look like smiling at you, but actually they’re just opening mouths.

Go to See the Mona Lisa?

There must be something about the mysterious(神秘的)smile. The 6 million people who visit the lady in the Louvre every year can’t all be wrong, after all. But they can be quite annoying standing in front of you, holding up their cameras to prevent you from seeing anything. In fact, it is hard for you to see the painting clearly because you have to stay away from it for security reasons. After queuing for hours, many tourists can remain in front of the painting only for 15 seconds at most.

If the mysterious lady in the picture knew her fate, she wouldn’t just be smiling, she’d be laughing.

So, still long to see the Mona Lisa? If you want to find out more about the list, read 101 Things NOT to Do Before You Die. Visit www.not2dobeforeidie.co.uk and buy the book at a 20% discount.

小题1:According to the passage, swimming with dolphins________.

A.is the world’s most popular tourist activity

B.gives fun to both tourists and dolphins

C.can cause danger to dolphins

D.will make tourists busy and tired小题2:What does the author think about going to see the Mona Lisa?

A.It is wrong to go and see the mysterious smile.

B.Queuing for hours is worthwhile.

C.Fifteen seconds in front of the painting is enough.

D.It is not as satisfying as expected.小题3:The list of “101 things not to do” is made most probably because its author_______.

A.thinks it boring to do the things suggested by other lists

B.believes other lists are not humorous enough

C.intends to persuade people to read more lists

D.wants to provide a list different from other lists小题4:What is the main purpose of the passage?

A.To introduce a website.

B.To advertise a book.

C.To comment on popular lists.

D.To recommend tourist activities.

题型:单项选择题

我国唯一的矿山安全单行法律是( )。

A.《矿山法》

B.《矿山安全法》

C.《矿山消防法》

D.《消防法》

题型:单项选择题

下面哪一种不能创建为WINDOWS的快捷方式()。

A.应用程序

B.数据文档

C.文本和文字

D.磁盘和文件夹

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