问题 单项选择题

关于碾压混凝土组成材料的要求,说法错误的是( )。

A.骨料的最大粒径以20mm为宜
B.使用的活性混合材料应合格
C.为使混凝土在水泥浆用量较少的情况下取得较好的和易性,可加入适量的引气剂
D.当混合材料掺量较高时宜选用普通硅酸盐水泥或硅酸盐水泥

答案

参考答案:C

阅读理解

阅读理解

                                                             Mapping Your World

       Different forms of maps are appearing.They allow independent travelers to get local knowledge of

places they are visiting, from the official to the unusual.Meanwhile, hitech developments are creating new

ways for us to map the world.Here are two of our favorites: 

      Green Maps

      Green Maps allows people to share with the world their knowledge of environmentally friendly places and attractions in the local areas.Users add information with a set of icons (图标) , making it easy to read any map, whatever the nationalities of those who produce it.At present there are over five hundred map

projects being developed in 54 countries.Green Maps' advertised idea is "think global, map local". It is a

wonderful way of gaining all sorts of information of a place, ranging from community gardens to good

places of birdwatching.

      Green Maps is not specifically intended for travelers.Not all of its maps are online, so it may be

necessary for some users to communicate with the producers through the Green Maps website.

      Map Mashups

      Many people use online maps developed by Google, but not many know about the mashups of them.Working in a similar way to Green Maps, Map Mashups allows people to add icons of their own to

existing maps to express a certain topic.The mashups is so called because it combines all the knowledge

you could ever need.It ranges from the extremely useful, such as where all the World Heritage Sites are, to the most bizarre (古怪的), such as where America's drunkest cities are.With the mashups added to the

basic Google Maps, a multilayered (多层的) map can be created.

1. According to the passage, which of the following is a characteristic of Green Maps?

A. Aiming at environmental protection.

B. Introducing local attractions with icons.

C. Offering advice to independent travelers.

D. Collecting icons worldwide for local maps.

2. Which of the following icons is most probably NOT used in Green Maps?

A.  

B.

C.  

D.

3. "Map Mashups" is named with the word "mashups" because ________.

A. it is produced by users all over the world

B. it gathers various kinds of information

C. it shares icons with Green Maps

D. it is a branch of Google Maps

4. What do Green Maps and Map Mashups have in common?

A. They are created by local people.

B. They are environmentally friendly.

C. Users can edit maps on the Internet.

D. Users need to communicate with producers.

单项选择题