Let us suppose it is now about A. D. 2060. Of course things have changed and life is very _____ .

Voyages to the moon are being made every day. It is as _____ to take a holiday on the moon today as it was for the people in the 1960s to take a holiday in Europe. At a number of _____ on the moon, many hotels have been built. The hotels are air-conditioned _____ In order that everyone can _____ the beautiful scenery on the moon, every room has at least one picture window. Everything imaginable is provided for the _____ of the young and the old.

What are people _____ now? People are still eating food. They haven’t yet started to take the electrical current or nuclear power as their _____ of energy directly. They may do this some day. But many kinds of foods now come _____ pill form, and the food that goes into the pill continues to mainly ______ green plants.

______ there are several times as many people in the world today as a hundred years ago, most of our planet’s surface has been filled. The deserts are ______ regularly with water and crops are no longer destroyed by pests (害虫). As a result, the ______ is always good.

Farming, of course, is very highly ______ Very few people have to work on the farm; it is possible to ______ the farm by just ______ a few buttons now and then.

People are now largely vegetarians (素食主义者). You see, as the number of people ______, the number of animals decreases. Therefore, people have to be vegetarians. And we are ______ both in our bodies and in our minds for we know the causes of diseases and pain and the ______ to them, and it is possible to ______ diseases.

Such would he our life in 2060.

   What makes us human？Is it our thoughts？Our emotions？Our behavior？

All of these things make us who we are，but at the center of it all lies the genome — the genes inside our bodies that determine everything from our hair color to our intelligence. But if we could change our genome，would we still be human？

Recently，a group of scientists from the US and South Korea worked together to successfully“edit”a human embryo（胚胎）and remove a genetic mutation（变异）that would have led to heart disease. This was achieved with the help of CRISPR-a gene — editing tool that allows scientists to edit the genome by cutting，changing or adding to parts of it.

Scientists involved in DNA editing are certain about the good of their work，and hope that in the future，diseases could simply be“edited out”.

However，others aren't so sure. People are worried that the science could be used not only to remove life-threatening illness，but also to make a“perfect”baby whose DNA has been chosen to improve its intelligence or other qualities. They say that this is a shallow way of thinking about raising children.

“It makes you think about who we are as people，and it makes you ask if humans should use the kind of power…that is changing human evolution（进化），”Jennifer Doudna of the University of California said.

Still，others worry that DNA editing could be turned into an expensive service that would only be available to the people who could afford it. That might mean the rich would be given another advantage in a world where they already have plenty of them.

“You could find wealthy parents buying the technology for their children, leading to even greater inequality than we already live with,”Marcy Darnovsky, director of the San Francisco Center for Genetics and Society, said.

How are you? I am chairman of Student Union, Li Hua. ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

I am looking forward to your reply.

Yours sincerely,

Li Hua

   Government intelligence agencies have a plan to build computers that store information inside DNA and other organic molecules（分子）.

Intelligence Advanced Research Projects Activity（IARPA）announced plans to develop tabletop-sized machines that can store and retrieve（取回）data from large batches of polymers — a term that refers to a wide variety of long，string-like molecules. Polymers can store data in individual atoms or groups of atoms.

The project is an attempt to solve a basic problem of the modern era:the vast and growing costs of data storage. Datacenters around the world sucked up 416. 2 terawatt hours of electricity in 2016. That's about 3 percent of the global supply，and it accounts for 2 percent of global greenhouse gas emissions.

A 2016 paper found that DNA，in particular，could store computer information more densely，require less energy，and survive higher and lower temperatures than conventional hard drives. The authors of that paper reported on the successes of prototype（雏形）DNA computers that used the genetic molecules for both long-term storage and random access memory（RAM）.

But no one has yet figured out how to handle DNA data storage on large scales.

IARPA officials said the new effort, called Molecular Information Storage, will be broken up into three periods:a two-year program to figure out how to store data in DNA or other molecules at high speed,a two-year program to figure out how to retrieve that data at high speed, and a two-year effort to develop an operating system that can run on that DNA.

Many of the technologies IARPA wants to develop are untested at these scales, so it's unclear how far away that proposed tabletop device really is.