1 . Age Reversal Technology

Our life spans (时间段) used to be relatively short.     1     Within the next 150 years, this was raised by medical advances. And fast forward to 2020 and global life expectancy is 72.6 years — higher than that in any country in 1950.

As people live longer, population aging becomes a greater economic problem. It has both placed a burden on public health spending and decreased productivity of workforce. And aging is the fundamental driver behind many diseases, such as cancer, heart disease, to name just a few. One expert in population aging at the European Molecular Biology Laboratory, Halldór Stefánsson, explains that some serious diseases related to aging — that very few people lived long enough to experience in the past — have replaced infectious diseases as the main cause of death.     2    

The amazing news is that age reversal technology will soon be a reality. On the bright side, the process of reversing aging is already possible for cells in scientific experiments.     3     In the foreseeable future, we will be able to enjoy a longer life as well. The goal is to preventively target aging — the major risk factor for a wide variety of diseases and disabilities — instead of treating one disease at a time, which is very costly. One future model projected an increase in NHS expense of £42 million year-on-year until 2031 due to the aging population.

    4    That means the technology will restore our vitality and bodily function by removing the damage inevitably caused by the processes of life.

A．And science has moved on to extend life spans of some animals, though not yet of humans.

B．Human aging timeline is also driven by other factors.

C．In the 1800s, life expectancy across the world was less than 40 years of age.

D．So, the question on all our mind is — can science stop aging?

E．Initially restricted to developed countries, population aging has also become a trend in the developing world.

F．Age reversal technology will also increase health span — the length of time during which one is healthy.

2 . Directions: Read the following passage. Fill in each blank with a proper sentence given in the box. Each sentence can be used only once. Note that there are two more sentences than you need.

Will Experimentation on Animals End?

One of the most debatable issues in science is the use of animals in research. Scientists experiment on animals for different reasons, including basic research to explore how organisms function, investigating potential treatments for human disease, and safety and quality control testing of drugs, devices and other products.

    1    However, opponents believe it is cruel and meaningless, as observations in animals often do not translate directly to humans.

In 1959, William Russell and Rex Burch proposed their “3Rs” guidelines for making the use of animals in scientific research more humane: restrict the use of animals; refine experiments to minimize distress; and replace tests with alternative techniques.     2     Around 29 million animals per year are currently used in experiments in the U.S. and Europeans Union countries. This is less than half the total in the mid-1970s —— a significant drop.

    3    Improvements in imaging methods that offer a look inside the bodies of animals allow scientists to get more and better data from each experiment than before.

For example, researchers previously had to do experiments with multiple mice at different stages of cancer development, but now they can watch the disease develop in a single living animal using a dye. Similarly, as brain-imaging techniques become more advanced, some questions that were addressed with experiments in monkeys before may be better answered by looking into the human brain now. “    4    ” says Larry Carbone, a senior veterinarian(兽医) at the University of California in San Francisco.

A．Over the course of five decades their guidelines have become widely accepted worldwide.

B．The awareness of animal protection contributes to the decline of the number.

C．Human volunteers must be able to replace monkeys more and more in the next 10 to 20 years.

D．New experimental techniques help to push numbers down.

E．Its supporters point to the long list of medical advances made possible with the help of animal research.

F．The number of the animals used in research is still considerable.