问题 单项选择题

当牙齿受力时,牙槽的张力侧发生的是()。

A.骨吸收

B.骨沉积

C.骨转换

D.骨粘连

答案

参考答案:B

实验题

(10,威海12)有三种失去标签的溶质质量分数分别为15%、l0%和5%的盐酸溶液。限定你选择下列仪器和药品,设计两种不局的实验方案,辨别出最浓的和最稀的盐酸溶液。

实验仪器:精密温度计、剪刀、镊子、量筒、秒表、烧杯、大试管、胶头滴管。

药 品:镁条

提 示:①镁条和盐酸反应速度很快,通过观察放出气泡速度很难准确判断盐酸浓度的大小,所以不建议用这种方法辨别之。②当你设计一种方案时,不必用到所有的仪器。③在描述每种实验方案时,要求说明:观察或测定何种变量、需要控制的条件、选用的仪器、实验步骤及结果与推论。

(1)实验知识和技能准备:

用量筒量取一定体积的液体时,正确的操作方法是___________________________________________

______________________________________________________________________________________________________________________________________________________________________________________

向试管中加入块状固体药品的方法是_______________________________________________________

___________________________________________________________________________________________

(2)把你设计的实验方案依次填写在下表中.

实验方案一:

你观察或

测定的量

需要控制

的实验条件

选用的

仪器

实验步骤结果与推论
     
 

实验方案二:

你观察或

测定的量

需要控制

的实验条件

选用的

仪器

实验步骤结果与推论
     
 

(3)为了排除实验过程中偶然因素的干扰,保证实验结果的可靠性,你认为还应该如何完善你的实验方案?

___________________________________________________________________________________________

阅读理解

The home of the future won’t be completely different and we will be living in houses and flats just as we do today. But people will want to shape their homes to match their dreams. No two homes will be the same. People will be able to buy “house kits” containing a basic house structure, with movable walls, doors and windows. They will put together the different parts to create the home they want.

Many jobs that we do today will disappear, others will still exist but will change and new jobs will be created. Skilled workers such as builders, gardeners and electricians won’t disappear because machines can’t replace them. Teachers will still exist because students need human contact. But they will be using modern technology in class more and students will be working more from home. The medical technology revolution and space travel will create new jobs which we can only imagine today.

Space holidays will develop in the future, but these holidays won’t be for everyone because they won’t be cheap. Short space trips will develop first, then space hotels will orbit the earth where it will be possible to have a longer vacation. By the end of the next century, there will be holiday centres on the moon with leisure facilities for families.

Paper won’t exist in the future. Instead, there will be e-paper which people will be able to use over and over again. This will develop in order to save natural resources. E-newspapers and e-magazines will replace traditional newspapers and magazines and we will download information and news articles from the Internet every day onto our reuseable paper.

The laws of physics tell us that the earth is going to disappear some time in the future. This isn’t going to happen tomorrow but scientists predict that it will happen in five billion years when our sun explodes(爆炸).We will have to explore the universe and find another home. At some point in the distant future, either we stay on the earth and die with it, or we leave and move to another planet. There won’t be any other choice.

60.Homes of the future will ________.

A.be completely different from those of today.

B.be very similar to our homes

C.all be different form one another                 

D.be movable as you want

61.Space trips and staying in space hotels will _________.

A.become a very common way to spend a holiday

B.be the cheapest holiday option for families

C.attract a lot of people

D.still only be for very rich people

62.E-paper will replace traditional paper because _________.

A.we will use it again  B.it won’t waste natural resource

C.it will be cheaper to produce   D.it will be convenient to carry

63.We will have move to another planet ________.

A.if we want to save the human race  B.when the sun explodes

C.when the earth disappears       D.when the earth is too crowded to fill people on