问题 选择题

I’ve become good friends with several of the students in my school __________ I met in the English speech contest last year.

A.who

B.where

C.when

D.which

答案

答案:A

who 表明先行词是人(一般在从句中充当主语)

which 表明先行词是物(也指事)在限定性定语从句中=that,在非限定性定语从句中只能which

where表明先行词是地点,when引导时间状语从句.句子中先行词the students是人,所以选A.

阅读理解

Chris is not a traditional explorer --- he usually works in an office for a large organization. However, Chris' job can be just as exciting and dangerous as being an explorer.

Chris works for MSF, an organization also known as .Doctors Without Borders. Since1971, MSF has sent trained doctors all over the world to help people who have suffered from disasters, such as wars and illnesses. Chris is a doctor from France who has traveled to many places to organize programs that help people.

At the moment, over 27,000 trained doctors have taken part in MSF projects. The organization received the Nobel Peace Prize in 1999. All kinds of doctors can volunteer for MSF. They need to be ready to go almost anywhere in the world and, of course, they should face difficulties. Most of MSF's work is in Africa. When MSF chooses a doctor for a task, they have to go for at least six months. When doctors have completed a few tasks, they might be sent on an emergency task following a disaster, such as an earthquake.

But why would doctors leave a comfortable life and a good pay to join MSF? According to Chris, the experience they have is a great help in their life. What's more, just like the explorers of the past, they need to keep an open mind and learn to get on well with the people they meet. One thing that they can say at the end of any task is that they have made a real difference to people’s lives.

小题1: What may MSF's work be like?

A.Tiring and boring.

B.Exciting and dangerous.

C.Relaxing and colorful.

D.Peaceful and comfortable.小题2:As a volunteer doctor for MSF, he or she should     .

A.have worked in Africa for six months

B.have been sent on an emergency task

C.be ready to work for a task for at least half a year

D.have suffered from wars, illnesses or other disasters小题3:. Why would doctors like to join MSF?

A.Because they can get a good pay.

B.Because they can have a comfortable life.

C.Because they can help others and get experience.

D.Because they can travel abroad with their families.小题4: What is the main idea of this passage?

A.Chris is a doctor who has organized programs to help people.

B.MSF received the Nobel Peace Prize for helping poor countries.

C.Volunteer doctors make a real difference to their own lives in MSF.

D.MSF offers medical help to people who have suffered from disasters.

实验题

阅读下列材料,回答相关问题:(8分)

勇敢向教条说“不”的约翰·格登

资料1 人类都是由受精卵发育而来,在受孕之后的最初几天,组成胚胎的都是未

成熟的细胞。这些细胞每一个都可以发育为成熟有机体中所有细胞类型的细胞。这种未成熟的细胞被称为多功能的干细胞或诱导多功能干细胞。随着胚胎的发育,多功能干细胞进一步形成神经细胞、肌肉细胞、肝脏细胞以及其他所有种类的细胞,这些细胞经过分化后,开始在人体内承担起特殊的机能。很长的一段时间里,人们普遍认为这一过程是单向的、不可逆的。成熟之后的细胞是不可能再回到未成熟、多能性的状态。

根据上图回答:

(1)A→B、B→C、C→D的过程是细胞的__________。在此过程中,首先是___________发生一系列的变化,由一个分成等同的两个;随后_________________也发生一定的变化,由一份分成大体相等的两份,最终每份中都含有一个____________________。

(2)D→E的过程是细胞的__________________。在此过程中细胞的形态、结构、功能发生了变化,但是细胞核内的________________没有发生变化。

资料2 但荣获2012年诺贝尔生理学或医学奖的英国发育生物学家约翰·格登却提出了自己的看法,他假设:这些细胞的基因组仍然包含着驱动它发育成机体所有不同类型的细胞所需的信息。在1962年,在一项经典实验中,他将一个青蛙卵细胞的细胞核替换为成熟肠细胞的细胞核。这个改变了的卵细胞发育成为了一只正常的蝌蚪。这一实验具有划时代的意义,首次证实了已分化的细胞可通过核移植技术将其重新转化为具有多能性的细胞。

起初,这一里程碑式的发现遭到了许多人的怀疑,不少科学家认为这完全不可能。但在重复实验的验证下,该结果最终被接受并引发了密集的研究。随着技术手段的发展,最终导致了哺乳动物的克隆,也使约翰·格登成为细胞核移植与克隆方面的先驱。他的研究告诉人们,一个成熟、已分化细胞的细胞核可以返回到未成熟、多能性的阶段,这为此后诱导多功能干细胞的研究埋下了伏笔。

(3)约翰·格登的研究说明,一个成熟、已分化细胞的细胞核可以返回到__________的阶段。

(4)改变了的卵细胞发育成为一只正常蝌蚪的过程中,要经过细胞分裂和分化形成生物体的各种____________,最终形成器官、系统构成生物体。