英语选修7 Unit 5 语篇专练二

语篇专练(二)

Ⅰ.阅读理解

A

Some people are calling it the greatest medical breakthrough so far this century.Surgeons

in Spain have successfully carried out the world’s first organ transplant using new stem cell

technology.

But what are stem cells？Most cells in our bodies are designed to serve specific

purposes，for example，a liver cell develops to work in the liver and cannot become a heart

cell.

But stem cells are different.They are very young，and in the laboratory scientists can

grow them into different types of cell.

Claudia Castillo needed a new windpipe after suffering from tuberculosis.Scientists from

the University of Bristol in the UK took a donor(捐献的) windpipe，from someone who had

recently died.

They used strong chemicals to remove the donor’s cells.This was done with cells from

Ms Castillo’s windpipe and nose，and stem cells from her bone marrow.After four days the

cells had grown sufficiently for the windpipe to be transplanted into Ms Castillo.

Currently，transplant patients have to take drugs for the rest of their lives to prevent their

bodies rejecting the new organs.These drugs can have bad side-effects，and do not always

prevent rejection.

But by using Ms Castillo’s own cells，doctors were able to trick her body into thinking

the new windpipe was her own organ.Five months on，Claudia Castillo is in perfect health.

This ground-breaking procedure could be used in other transplant operations in the

future.Scientists also believe stem cells might be used to treat Parkinson’s disease，Alzheimer’s disease，heart disease，stroke，arthritis，diabetes，burns and spinal cord damage.

However，stem cell research is extremely controversial.The most effective stem cells do

not come from adults but from embryos(胚胎) created in laboratories and which are just a few

days old.Many people have religious or ethical objections to growing embryos，even if they

can be used to cure diseases.

1．The underlined word “it” in the first paragraph probably means “________”．

A．the way to develop the stem cell

B．the first organ transplant with the new stem cell technology

C．a new technology that can cure all diseases D．the discovery of a new stem cell

2．According to the text，stem cells ________.

A．are the most successful medical breakthrough

B．are not designed to serve special aims

C．can be developed into various cells

D．only come from donors

3．Which of the following is Not True about Claudia Castillo?

A．Her operation had been done successfully.

B．Drugs were used in her transplant.

C．Her own cells were used in the transplant.

D．She was tricked by the scientists.

4．It can be inferred from the text that ________.

A．transplant operations could be widely used with time going on

B．drugs taken by transplant patients have few bad side-effects

C．most people are strongly against growing embryos

D．scientists believe stem cells are the best choice now

B

What will power your house in the future？According to scientists at the Massachusetts

Institute of Technology (MIT) in the US，it might be artificial leaves.

Natural leaves can change sunlight and water into energy.It is known as

photosynthesis(光合作用)．Now researchers have found a way to imitate this process.

The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a

special silicon chip with catalysts(催化剂)．Similar to natural leaves，it can split water into

hydrogen and oxygen when put into a bucket of water.The hydrogen and oxygen gases are

then stored in a fuel cell，using those two materials to produce electricity，located either on top

of a house or beside the house.

Though the leaf is shaped like a poker card，scientists stated that it is promising to be an

inexpensive somtoe of electricity in developing countries.“One can imagine villages in India

and Africa not long from now purchasing an affordable basic power system based on this

technology，” said an American scientist，Docera.

An artificial leaf is not a new idea.The first artificial leaf was invented in 1997 but too

expensive and unstable for practical use.The new leaf，however，is made of cheap materials，easy to use and highly stable.In laboratory studies，Nocera showed that an artificial leaf could

operate continuously for at least 45 hours.

The wonderful improvements come from Nocera’s recent discovery of several powerful new，inexpensive catalysts.These catalysts make the energy transformation inside the leaf

more efficient with water and sunlight.Right now，the new leaf is about 10 times more

effective at carrying out photosynthesis than a natural one.Besides，the device can run in

whatever water is available.

Hopefully，each home could possibly have the access to the new application in the future.